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Chrome 70 beta: shape detection, web authentication, and more

Unless otherwise noted, changes described below apply to the newest Chrome Beta channel release for Android, Chrome OS, Linux, macOS, and Windows. View a complete list of the features in Chrome 70 on Chrome 70 is beta as of September 13, 2018.

Shape Detection Origin Trial

The Shape Detection API makes a device's shape detection capabilities available on the web, letting you identify faces, barcodes, and text in images. It does this without the use of a performance-killing library. As Chrome 70, this API is available for experimentation through a Chrome origin trial.

The Shape Detection API consists of three APIs: A Face Detection API, a Barcode Detection API and a Text Detection API. Given an image bitmap or a blob, the Face Detection API returns the location of faces and the locations of eyes, noses, and mouths within those faces. To give you rudimentary control of performance, you can limit the number of returned faces and prioritize speed over performance. The Barcode Detection API decodes barcodes and QR codes into strings. (There is a QR code demo at The value can be anything from a single set of digits to multi-line text. The Text Detection API reads Latin-1 text (as defined in iso8859-1) in images. All of these APIs only expose what's supported in the underlying device.

A short example will give you a taste of these APIs, all of which work in a similar fashion. The code below finds all barcodes or QR codes in a given image and prints their values to the console.

const image = document.getElementById('someImage');
try {
const barcodeDetector = new BarcodeDetector();
const barcodes = await barcodeDetector.detect(image);
barcodes.forEach(barcode => console.log(barcodes.rawValue));
} catch (exception) {
console.error('Boo! Barcode detection failed:', exception);

Web Authentication

Chrome 70 has two updates to the Web Authentication API related to the PublicKeyCredential type.

The Credential Management API, enabled in Chrome 51, defined a framework for handling credentials that included semantics for creating, getting, and storing them. It did this through two credential types: PasswordCredential and FederatedCredential. The Web Authentication API adds a third credential type, PublicKeyCredential, which allows web applications to create and use strong, cryptographically attested, and application-scoped credentials to strongly authenticate users. The PublicKeyCredential type was enabled by default on desktop in Chrome 67. In Chrome 70 it is also enabled by default on Android.

Also enabled by default are macOS's TouchID and Android's fingerprint sensor via Web Authentication. These allow developers to access biometric authenticators through the Credential Management API's PublicKeyCredential type.

A Web Authentication verification screen

Other Features in this Release

Displaying a dialog causes pages to lose fullscreen

Dialog boxes, specifically authentication prompts, payments, and file pickers require context for users to make decisions. Fullscreen, by definition is immersive, and removes the context that a user needs to make a decision. Chrome now exits full screen whenever a page shows a dialog box.


Add referrerpolicy support to <script> elements

Many resource-fetching elements have support for the referrerpolicy attribute, which lets developers provide a keyword to influence the value of the Referer HTTP header that accompanies a request. The <link> element already has support for this, so it is technically possible to preload a script with a developer-set referrer policy. Starting in this version of Chrome, the <script> element supports the referrerpolicy as well.

The <rp> element defaults to display:none

The default style of the <rp> element is changed to display:none instead of display:inline even if it is not inside the <ruby> element as defined in the HTML specification. This behavior is implemented in the user agent stylesheet, but the web author can override it.

Intervention Reports

An intervention is when a user agent does not honor an application request for security, performance, or annoyance reasons. With this change, Chrome can be configured to send intervention and deprecation messages to your servers using the Report-To HTTP Response header field and surface them in the ReportingObserver interface. This is the first of several proposed uses for the Report-To header. Follow these links to learn more about the header and the interface.


Support codec and container switching with MSE using SourceBuffer.changeType()

This change adds the SourceBuffer.changeType() method to improve cross-codec or cross-bytestream transitions during playback with Media Source Extensions.

Support Opus in mp4 with Media Source Extensions

Opus is an audio codec already supported by the HTML5 src attribute on <url> elements. It is now supported by Media Source Extensions.

'name' attribute for dedicated workers

Dedicated workers now have a name attribute, which is specified by an optional argument on the worker's constructor. This lets you distinguish dedicated workers by name when you have multiple workers with the same URL. Developers can print name in the DevTools console which will make it easier to debug workers. When the name parameter is omitted, an empty string is used as the default value. For more information, see the discussion on GitHub.

ontouch* APIs default to disabled on desktop

To avoid confusion on touch feature detection, ontouch* members on window, document, and element are disabled by default on desktop (Mac, Windows, Linux, ChromeOS). Note that this is not disabling touches, and usage such as addEventListener("touchstart", ...) is not affected.

Options dictionary for postMessage methods

An optional PostMessageOptions object has been added as an argument to postMessage() for 6 of the 7 interfaces where it's supported, specifically, DedicatedWorkerGlobalScope, MessagePort, ServiceWorker, ServiceWorker.Client, Window, and Worker. This gives the function a similar interface on its definitions and allows it to be extended in the future. Because broadcastChannel.postMessage() doesn't take additional arguments (such as transfer) it is not being changed.


This  getConfiguration() was implemented according to the WebRTC 1.0. Specifically it returns the last configuration applied via setConfiguration(), or if setConfiguration() hasn't been called, the configuration the RTCPeerConnection was constructed with.


A description property is being added to Symbol.prototype to provide a more ergonomic way of accessing the description of a Symbol. Previously, the description could only be accessed indirectly through Symbol.protoype.toString().

TLS 1.3

TLS 1.3 is an overhaul of the TLS protocol with a simpler, less error-prone design that improves both efficiency and security. The new design reduces the number of round-trips required to establish a connection and removes legacy insecure options, making it easier to securely configure a server. It additionally encrypts more of the handshake and makes the resumption mode more resilient to key compromise.

Update behavior of CSS Grid Layout percentage row tracks and gutters

Percentage row tracks and gutters in grid containers now have indefinite heights. Previously, these were behaving similarly to percentage heights in regular blocks, but the CSS Working Group has resolved to make them behave the same as for columns, making them symmetric. Percentages are now ignored when computing intrinsic height and resolved afterwards against that height. That way both column and row axes will have symmetric behavior to resolve percentages tracks and gutters.

Web Bluetooth available on Windows 10

Web Bluetooth allows websites to communicate over GATT with nearby user-selected Bluetooth devices in a secure and privacy-preserving way. In Chrome 56, this shipped on Android, ChromeOS, and macOS. In Chrome 70 it is shipping on Windows 10. For earlier versions of Windows and Linux, it is still behind a flag (chrome://flags/#enable-experimental-web-platform-features).

WebUSB on Dedicated Workers

WebUSB is enabled inside dedicated workers. This allows developers to perform heavy I/O and processing of data from a USB device on a separate thread to reduce the performance impact on the main thread.

Deprecations and Interoperability Improvements

Chrome sometimes deprecates, removes, or changes features to increase interoperability with other browsers. This version of Chrome includes the following such changes.

Remove AppCache from insecure contexts.

AppCache is now removed from insecure contexts. AppCache is a powerful feature that allows offline and persistent access to an origin, which is a powerful privilege escalation for cross-site scripting. This removes that attack vector by only allowing it only over HTTPS. Developers looking for an alternative to AppCache are encouraged to use service workers. An experimental library is available to ease that transition.

Remove anonymous getter for HTMLFrameSetElement

The anonymous getter for HTMLFrameSetElement is non-standard and therefore removed.

Deprecate and remove Gamepads.item()

The legacy item() accessor is removed from the Gamepads array. This change improves compatibility with Firefox which is so far the only browser to implement GamepadList.

Deprecate Custom Elements v0

Custom Elements are a web components technology that lets you create new HTML tags, beef up existing tags, or extend components authored by other developers. Custom Elements v1 have been implemented in Chrome since version 54, which shipped in October 2016. Custom Elements v0 is now deprecated with removal expected in Chrome 73, around March 2019.

Deprecate HTML Imports

HTML Imports, which allow HTML to be imported from one document to another, are now deprecated. Removal is expected in Chrome 73, around March 2019. Sites depending on HTML imports already require a polyfill on non-Chromium browsers. When HTML imports is removed, sites that have the polyfill should continue to work on Chrome.

Deprecate Shadow DOM v0

Shadow DOM is a web components technology that uses scoped subtrees inside elements. Shadow DOM v1 has been implemented in Chrome since version 53, which shipped in August of 2016. Shadow DOM v0 is now deprecated with removal expected in Chrome 73, around March 2019. Sites depending on HTML imports already require a polyfill on non-Chromium browsers. When Shadow DOM v0 is removed, sites that have the polyfill should continue to work on Chrome.

Deprecate SpeechSynthesis.speak() without user activation

The speechSynthesis.speak() function now throws an error if the document has not received a user activation. This API is being abused by sites since it is one of the only remaining APIs which does not adhere to autoplay policies in Chrome.

10 years of Speed in Chrome

Speed has been one of Chrome’s four core principles, since it was first launched ten years ago. We’ve always wanted to enable web developers to provide users with fast, engaging web experiences. On Chrome’s 10th birthday, we thought it would be fun to look at what we’ve done to improve speed over the years and what we’re doing next.

Many components in the browser contribute to speed

V8 is Chrome’s JavaScript and WebAssembly engine. With web pages using an increasing amount of JavaScript, a fast engine to handle it is an important cornerstone. Over the years, we worked on a new JavaScript execution pipeline for V8, launching Ignition (a new interpreter) and TurboFan (an optimizing compiler). These allowed us to improve performance on the Speedometer benchmark by 5-10%. Script streaming enabled us to parse JavaScript on a background thread as soon as it began downloading, improving page loads by up to 10%. We then added background compilation reducing main-thread compile time by up to 20%.

Our work on project Orinoco enabled concurrent garbage collection, freeing up the main thread and reducing jank. Over time, we also shifted to focusing on real-world JavaScript performance, helping us double the performance of the React.js runtime and improve performance for libraries like Vue.js, Preact, and Angular up to 40%. Parallel, concurrent, and incremental garbage collection reduced garbage collection induced jank by 100× since the initial V8 commit. We also implemented WebAssembly, enabling developers to run non-JavaScript code on the web with predictable performance, and launched the Liftoff baseline compiler to ensure fast startup times of WASM apps. These new components are just the latest in a 10-year effort that has improved V8's performance release-to-release for an improvement of 20x over the years.

V8 Bench scores for a range of Chrome releases over the years. V8 Bench is the predecessor to the old Octane benchmark. We've used it for this chart because unlike Octane, it can run in all Chrome versions, including the initial Chrome Beta.

Chrome has also played a key role in helping evolve network protocols and transport layers through SPDY, HTTP/2 and QUIC. SPDY aimed to address limitations of HTTP/1.1 and became the foundation of HTTP/2 protocol, which is now supported by all modern browsers. In parallel, the team has been actively iterating on QUIC, which aims to further improve latency and user experience and now has an active IETF effort behind it. QUIC’s benefits are noticeable for video services like YouTube. Users reported 30% fewer rebuffers when watching videos over QUIC.

Next up is Chrome's rendering pipeline. This is responsible for ensuring webpages are responsive to users and display at 60 frames per second (fps). To display content at 60fps, Chrome has 16ms to render each frame. This includes JavaScript execution, style, layout, paint and pushing pixels to the user's screen. Of this 16ms, the less Chrome uses, the more web developers have to delight their users. Improvements to our rendering pipeline have included optimizing how we identify which elements in a page need to be redrawn and better tracking visually non-overlapping sets. This reduced the time to paint new frames to the screen by up to 35%.

In 2015, a user-centric performance model called RAIL was introduced by the Chrome team. We recently updated it.

What about memory consumption? Between Chrome 63 and 66, a ~20-30% improvement in renderer process memory usage was observed. We hope to continue exploring ways to build on this now that site-isolation has landed. Ignition and TurboFan reduced V8's overall memory footprint, slimming it down by 5-10% on all devices and platforms supported by V8. Some sleuthing this year also discovered memory leaks impacting 7% of sites on the web, which we’ve now fully fixed. Many components contribute to Chrome’s speed including the DOM, CSS and storage systems like IndexedDB. To learn more about our improvements to performance, continue keeping an eye on the Chromium Blog.

Give web developers more power to measure and optimize their web pages

Understanding where to start with improving your site can be a tedious process. To help, we explored several tools for understanding the lab signals and real-world experience felt by your users. Over the years, the Chrome DevTools Performance panel became a powerful way to visualize the play-by-play breakdown of how web pages were displayed in a lab setting. To continue lowering the friction for finding performance opportunities sites had, we then worked on Lighthouse - a tool for analyzing the quality of your website, giving you clear measurements of your site’s performance and specific guidance for improving your users’ experience. Lighthouse can be accessed directly from inside the DevTools Audits panel, run from the command-line, or integrated with other development products like WebPageTest.
Lighthouse running in the Chrome DevTools Audits panel

To complement the lab data provided by Lighthouse, we released the Chrome User Experience Report to help developers get access to field metrics for the experience their users feel in the real-world, such as First Contentful Paint and First Input Delay. Now, developers can build out their own custom site performance reports and track progress over millions of origins using the CrUX Dashboard.

We also introduced a number of Web Platform capabilities to help developers optimize the loading of their sites. We shipped Resource Hints and <link rel=preload> to allow developers to inform the browser what resources are critical to load early on. Chrome was one of the first browsers to implement support for byte-saving approaches like Brotli for compression, WOFF2 for smaller web fonts and WebP support for images.
We’ve been excited to see an increasing number of browsers support these features over time. Chrome implemented Service Workers, enabling offline caching & network resilience for repeat visits to pages. We’re delighted to see broad modern browser support for the feature.

In fact, Google Search now uses Service Worker and navigation preload for opportunistic caching on repeat searches. This led to a 2x improvement in page load times for repeat visits.
As we look to the future, we are also excited about the potential that emerging standards like native lazy-loading for images & iframes, and image formats like AV1 have to help deliver content to users efficiently.

Enjoy more of the web on your data-plan with Chrome

Over the last 10 years, the size of web pages has been ever-increasing, but for many users coming online for the first time, data can be prohibitively expensive or painfully slow. To help, Chrome released data-conscious features over the years like Chrome’s Data Saver. Data Saver intelligently optimizes pages, saving up to 92% on data consumption.

Going ahead, we are exploring new ways to help you save data. For users on the slowest connections, we've been working on Chrome for Android, allowing for smarter page optimizations to show essential content earlier. These page transformations load far faster than the full page, and we're continuing to improve our fidelity, coverage, and performance.

We've also been experimenting with putting guardrails in place for users who are data- or network- constrained. For example, we're exploring bringing native lazy-loading to Chrome, as well as providing users the option to stop additional requests from a page when it uses a lot of data.

We’re just getting started...

Together, these changes help developers and businesses deliver useful content to their users sooner. We know there’s still work to be done. Here’s to offering improvements to page load performance over another 10 years!

Posted by Addy Osmani, JavaScript Janitor

How we designed Chrome 10 years ago

NOTE: This article was inspired by a conversation with Darin Fisher, VP for Google Chrome, for our YouTube series “Designer vs. Developer”.

To release a browser when there were already established ones in the market was a bold move—especially when some of the major browsers were clocking over a million downloads within just hours of their release.
The community speculated about a Google browser as early as 2004, but the team actually started working on the project in 2006. With the rise in rich web applications such as Gmail, YouTube, and Google Maps, the demand for more powerful browsers became apparent. These new web apps were processor-intensive and the browsers weren’t designed to handle that level of complexity.

“In your typical browser of that day, if you were to leave Gmail running overnight, you would come back the next day and your browser would feel pretty sluggish.”
– Darin Fisher, VP Chrome

Browsers of that time mimicked what early search engines had done, diluting the focus on the core user experience. Search engines were mostly portal sites with a sea of links and a tiny input field. Google Search stripped away the clutter, offering the user a single input field, and focused on a single task.

Web browsers had created a similar problem with excessive toolbars. Whenever users installed a new app, they were offered an extra toolbar. Eventually, the browser UI dominated the user's screen real estate and left very little space for content. Chrome wanted to do what Google did with search: focus on content. The team wanted to get out of the user’s way and include features that weren’t possible before, such as draggable tabs. Even the extension system was built to ensure that the screen space for content wasn’t compromised and that the surrounding UI was minimized as much as possible.

The mantra for Chrome was the four S’s: simplicity, speed, security, and stability.

Simplicity represented the streamlined UI design and experience. Speed was about how quickly the browser responded when a user performed an action. Speed wasn’t just about load time, either. Before Chrome, browsers would often hang or fail to respond when a user tried to close a tab, had too many tabs open, or was doing something complicated on a page. Chrome worked on a multiprocessor architecture, so if the user clicked to close a tab, it would simply close.

Security was about making users feel safe on the web, protecting them from any nasties on the internet such as viruses or fake sites, and giving them control over what was happening. This tied into the final S -- Stability of the browser, ensuring that it wouldn’t randomly crash. The team put a lot of effort in making sure it supported the many quirks on the web and rendered pages in a way that web developers intended.

I asked Darin about the things he is proud of and the decisions he regretted. He mentioned the liberation of starting with the Windows version, which meant his teams could focus on building a great browser without thinking about any cross-platform issues. While it maintained the free-spirit of development for the team, to their peril, they had to recreate everything from scratch when building for mobile, MacOS and Linux - a painful but critical learning of ‘thinking long-term’ for him and the team.

The other challenge I asked him about was the dreaded “best viewed in browser X” banner message that was common in the early 2000s, indicating that site content might not show properly on some browsers (including Chrome). Today, Chrome is working with other browsers vendors, the W3C committee, and especially developers, to make sure we’re solving the right problems for the community, such as the cross-collaboration work we did when implementing CSS Grid.

What do the next ten years hold? As new computers, mobile devices, and users come online, the most likely effect will be that design patterns and trends from Asia and Africa become the standard way of experiencing digital design. Web makers in India have pioneered offline experiences, and app designers in Nigeria are developing new ways of delivering Ecommerce experiences to users on 2G networks.

So, here’s to the next ten years. Happy birthday, Chrome!

Posted by Mustafa Kurtuldu, Design Advocate

10 Years of Chrome DevTools

Chrome is turning 10! Thank you for making the web development community so open, collaborative, and supportive. DevTools draws inspiration from countless other projects. Here’s a look back at how DevTools came about, and how it’s changed over the years.

In the beginning, there was Firebug

Imagine for a moment that browsers didn't ship with developer tools. How would you debug JavaScript? You'd basically have 3 options:
What about layout issues? Network errors? Again, all you could really do is conduct painstaking experiments in your code. This was the reality of web development up until 2006. Then a little tool called Firebug came along and changed everything.

A screenshot of Firebug's Net panel, taken from
Saying Goodbye to Firebug (source and license)

Firebug was a Firefox extension that let you debug, edit, and monitor pages in real-time. As a web developer suddenly you went from having no visibility into your pages to having what are essentially the core features of modern developer tools. The ability to understand exactly why Firefox was behaving as it was unleashed a flood of creativity on the web. Without Firebug, the Web 2.0 era wouldn't have been possible.

WebKit Web Inspector

Around the same time as Firebug’s launch, a few Google engineers started working on a project which would eventually lead to Chrome. From the start, Chrome was a mashup of different code libraries. For rendering the Chrome engineers opted for WebKit, which is the open-source project that still powers Safari to this day. An added bonus of using WebKit was that it came with a handy tool called the Web Inspector.

A screenshot of the Web Inspector, taken from Web Inspector Redesign (source and license)

Like the Net panel of Firebug, the original Web Inspector probably looks familiar. Much of its functionality lives on to this day as the Elements panel in Chrome DevTools. Web Inspector launched a few days after Firebug, and Safari was the first browser to bundle developer tooling directly into the browser.

The "Inspect Element" era

Chrome brought many innovative ideas to the browser ecosystem, such as the omnibox that combined search and the address bar, and a multi-process architecture that prevented one hanging tab from crashing the entire browser. But the innovation we like the most was providing developer tools in every build to every user, exposed with the click of a mouse.

"Inspect Element" in 2010

Before Chrome, developer tooling was an opt-in experience. You either had to install an extension, like Firebug, or enable some flags, as is still the case in Safari today. Chrome was the first browser to make developer tooling accessible from every browser instance. We'd like to claim that we had a grand vision for creating a developer-friendly browser from the start, but the reality is that Chrome had a lot of compatibility issues in its early days (which makes sense, since no one was building for it) and we needed to give web developers an easy way to fix these issues. Web developers told us that it was a useful feature, and we kept it.

The mobile era

For the first few years of the DevTools project, we essentially added chapters to the stories that Firebug and Web Inspector started. The next big shift in how we approached DevTools happened when it became clear that smartphones were here to stay.
Our first mission in this brave new world was to enable developers to debug real mobile devices from their development machines, which we call remote debugging. DevTools was actually well-positioned to handle remote debugging, thanks to another consequence of Chrome’s multi-process architecture. Early on in the DevTools project we realized that the only way a debugger could reliably access a multi-process browser was through a client-server protocol, with the browser being the server, and the debugger being the client. When mobile Chrome came around, the protocol was already baked into it, so we just had to make the DevTools running on your development machine communicate with the Chrome running on your mobile device over the protocol. This protocol still forms the backbone of DevTools today, and is now known as the Chrome DevTools Protocol.

Remote Debugging

Remote debugging was a step in the right direction, and to this day is still the primary tool for making sure that your sites behave reasonably on real mobile devices. Over time, however, we realized that remote debugging could be a bit tedious. When you're in the early phases of building out a site or feature, you usually just need a first-order approximation of the mobile experience. This prompted us to create a set of mobile simulation features, such as:

  • Precisely emulating the mobile viewport, simulating touch-based input and device orientation.
  • Throttling the network connection to simulate 3G and CPU to simulate less-powerful mobile hardware.
  • Spoofing user agent, geolocation, accelerometer data and more.

We collectively refer to these features as Device Mode.

An early prototype of Device Mode

Device Mode in 2018

The performance era

While the mobile era unfolded, big apps like Gmail were pushing the limits of the web's capabilities. Gmail-scale bugs called for Gmail-scale tools. One of our first major contributions to the tooling ecosystem was to show a play-by-play breakdown of exactly everything that Chrome had to do in order to display a page.

The original Timeline panel, as announced in Do More with Chrome Developer Tools

The Performance panel in 2018

These tools were a step in the right direction, but in order to spot optimization opportunities you needed to learn the nitty-gritty details about how browsers work and sift through a lot of data. Lately we've been building on this foundation to provide more
guided performance insights. The new Lighthouse engine powers the Audits panel, and is also available as a Node module for integration with CI systems.

Performance suggestions in the Audits panel

The Node.js era

Up until 2014 or so, we mainly thought of DevTools as a tool for building great experiences on Chrome. The rise of Node prompted us to rethink our role in the web ecosystem.
For the first few years of Node's existence, Node developers were in a situation similar to that of web developers before Firebug, or Gmail developers before the Timeline panel: the scale of Node apps outpaced the scale of Node tools. Given that Node runs on Chrome's JavaScript engine, V8, DevTools was a natural candidate to fill the gap. Support for debugging Node with DevTools landed in 2016 and includes the usual DevTools features, such as breakpoints, code stepping, blackboxing, source maps for transpiled code, and so on.
Node Connection Manager

The DevTools protocol ecosystem

The name Chrome DevTools Protocol (CDP) suggests an API that only DevTools can use. The reality is more general than that: it’s the API that enables programmatic access to Chrome. Over the last few years, we've seen a few third-party libraries and applications join the protocol ecosystem:
  • chrome-remote-interface provides low level JavaScript access to the protocol
  • Puppeteer brings it to the next level of abstraction and enables automation of the evergreen headless Chrome browser with modern JavaScript API
  • Lighthouse automates the process of finding ways to improve the performance and quality of pages

We're excited to see thousands of projects depend on these packages to enable rich interaction with Chrome. If you’re in the tooling or automation business, it’s worth checking out the protocol to see if it opens up any opportunities in your domain. For example, the VS Code and WebStorm teams both use it to enable JavaScript debugging within their respective IDEs.

What's next?

Our core mission is to build tools that help you create great experiences on the web. We very much rely on your feedback to help us determine what products or features to build.

Thank you for creating such a vibrant community. We look forward to another 10 years of building the web with you.

Posted by the Chrome DevTools team

The ‘Capable Web’: A 10 Year Retrospective

When we introduced Chrome in 2008, our goal was to “keep evolving with the web and continuing to build a solid foundation for modern web applications.” In honor of our tenth year, we’d like to highlight some of the major changes in the web’s rich capabilities that we feel lucky to share with other browser vendors.

As the very first pages were served on the open web in 1990, people recognized that the ability to deliver dynamic content would make the web unique—you could provide information and function just by sharing a URL. The Common Gateway Interface standard released in 1993 defined a simple interface for web servers to run code in response to web requests. It brought a new era of experience and capability to computing, accessible at the click of a link. Hop forward two short years to JavaScript, then another year to frames, specifically the <iframe> tag. These innovations let developers dynamically load content into pages, brought a new level of interactivity to the web, and increased user expectations of what could be done in the browser.

Accessibility, linkability, indexability, and universal reach have always been the web’s core strengths. Alongside these super powers, users want ever richer and more-engaging experiences. “Ajax” was coined in 2005 to describe the combination of asynchronous JavaScript and XML, which shaped a more interactive, modern web. It led to the creation of such services as Google Maps, cementing the web as the best way to deliver experiences available to anyone, on any device.

2008 – 2014: Web applications, HTML5, and the start of the mobile era

Chrome saw huge progress in its early years, with a large number of what are now considered “core APIs” coming to the web after the WebKit implementation. The video, audio, and canvas elements were some of the first “modern web” features that many of us distinctly remember (and who can forget border-radius?). These features brought a new level of interaction to web experiences, and meant developers no longer needed plugins such as Adobe Flash or Java, to build interactive media and graphical experiences. Chrome experiments have captured great examples of rich experiences that are a direct result of the web’s improved performance.

The “Mobile Web” really hit the world in 2010, and we saw a slew of new platform primitives introduced for the platform (many inspired directly by Google Gears) to help make building web apps easier. We could now make responsive, offline-enabled applications with AppCache and WebSQL, request permission to access the user's geolocation, and even understand the orientation of the user’s device.
WebSocket landed on the platform the same year, heralding a change in the types of experiences developers could deliver on the web. No longer did they have to use long polling to enable a bi-directional channel between the user and a service; developers now had a two-way channel with a simple API to provide real-time communication.

Plink is an interactive music experiment synchronising player state via websockets.

Four major APIs came to Chrome in 2011. WebGL, Web Audio, and the Fullscreen API let us build rich and immersive experiences that could take advantage of the entire screen. IndexedDB — a new “web-first” storage mechanism — us store and query serializable JavaScript objects such as Strings, Objects, Arrays, Files, and Blobs more effectively.

Chrome Web Lab was an experiment that bridged the physical and digital worlds. It used Web Socket, video, real-time streaming, WebGL, and Web Audio to create an immersive world.

A bumper year for game-changing experiences on the web arrived in 2012. On the back of WebGL and Fullscreen, the Pointer Lock and Gamepad APIs let us build games and other web experiences that felt really interactive. The game-changing collection of WebRTC APIs truly set the web apart from all of the other platforms: It let us build P2P video-chat and real-time data sharing, without any plug-ins or proprietary stack, and accessible by simply clicking a link.

One of the first Chrome on Android to Chrome on Android WebRTC calls (March 2013)

In just seven years, the web changed drastically. Browsers got significantly faster and more capable, letting developers build richer experiences on the desktop. Users started to consume even more content on mobile, meaning we all had to rethink how our experiences would work across devices and form-factors, even when the user had no connectivity.

2015-2018: PWA, The Extensible Web, and deeper integration era

In 2015, we experienced a fundamental change in how we thought about integrating capabilities into the web platform. The Extensible Web manifesto asked browser engineers to consider a layered platform that offered lower-level primitives that were easier to explain, more efficient to implement, and allowed web developers to easily build higher-level abstractions, thus increasing the cadence and availability of compelling new features. Service Worker is an example of building on these APIs to follow these principles. Service Worker is a small piece of JavaScript that sits between the browser and the network, and lets the developer decide what to do with any web requests.

The combination of Service Worker and a handful of new APIs allowed marked the beginning of the Progressive Web Apps (PWA) era. PWAs are high-quality sites that combine the reach of the web with the user expectations that come with native platforms. Specifically, PWAs are...
  • Fast—they load instantly
  • Reliable—they never show the “downasaur,” even in uncertain network conditions, by taking advantage of the Service Worker and Cache APIs
  • Engaging—they respond quickly to user interactions with silky-smooth animations and no janky scrolling
  • Capable—the sites feel like natural extensions on the device, with immersive user experiences provided by features such as “fullscreen” and standalone mode through Web App Manifest; they deliver capabilities for meeting specific business goals, such as re-engagement through the Add to Homescreen feature and Web Push notifications

As PWAs became more established, so did the capabilities of the platform. The Background Sync API brought increased opportunities for developers to improve the resilience of their applications. We also got a better understanding of the network capabilities with extensions to the Network Information API.

Pointer Events, a critical component for any web site or app, came to Chrome after a long wait. Pointer Events presented a unified model for handling all forms of gesture-based input, ranging from touch to pens to mouse pointers.

In 2017, deeper integration of web apps with the host operating system and secure access to devices around the user arrived..

The Image Capture and Media Capture APIs provided full-frame access and control over a phone camera, as well as from other input sources such as a canvas. The Web Share API let sites share data directly with the operating system’s native sharing systems.

The Web Bluetooth API let a user securely select a Bluetooth LE device and have a webpage interact with the device. The Web USB API enabled the same level of connectivity, but to devices connected to the user's machine.

WebAssembly (WASM) opens up many possibilities. It brings a runtime that can execute code at near-native performance. Plus, it opens a new world of experiences on the web by letting developers use existing codebases built for other platforms on the web platform.

Web VR came to the web at roughly the same time it came to native platforms. It let us deliver immersive experiences without installing an app, significantly reducing the gap between a new native primitive arriving on platforms and being available across the web platform.

Forward to the future

We’re excited about the possibilities of the web platform. The web can (and should) be feature-rich, but new capabilities don't always have to be more complex. Web development should be predictable, manageable, and pain-free. Coming APIs such as Feature Policy are great examples of additions that will help developers create amazing sites in a more predictable way, and provide more control and customization over the UX of certain browser features. Feature Policy is the browser's built-in guide rails to help web developers avoid common pitfalls and use best practices.

Layered APIs is another initiative that we're excited about. With it, developers will be able to load and use high-level features shipped directly into the browser as JS modules. For example, instead of building a custom virtualize-scrolling component, developers can just import and use <virtual-scroller> in a site. Layered APIs can be quickly iterated on by the standards bodies and implemented by browser vendors, and will help create a pay-as-you-go standard library for the web. And looking further, the Houdini and Web XR APIs will radically change experiences we can build on and with the web.

Over the last 10 years, we’ve seen a massive increase in the rate at which new primitives and capabilities can be introduced to the web. We can thank all the browser vendors for their continued work to create and iterate on specs, using streamlined processes like those defined by the WICG and based on the principles in the Extensible Web Manifesto. We’ll continue our commitment to work with browser vendors and the developer ecosystem to prioritize features that users need, and to ensure that those capabilities arrive in a “webby” way. By doing so, we can uphold our original mission, while also prioritizing user safety, discoverability, instant access, and universal reach for everyone on the planet.

Here’s to the future of an even-more-capable open web.

Posted by Paul Kinlan, the Wizzy Web Warrior.

Charting Browser Interoperability

At this year's Google I/O, Ben Galbraith and Malte Ubl presented a chart during the Web keynote showing how the web is getting more interoperable:

This trend is really important to the Chrome team: web developers should be able to target the web platform, not four different (though overlapping) platforms. The chart was gleaned from the data in our Web API Confluence Dashboard. This project, originally designed for browser engineers, provides insights into web interoperability by tracking page-visible JavaScript APIs across many releases of the four major browser engines. Here’s an example:
Caption: Count of browser-specific APIs goes up when browsers are first to ship a new API, and down when either (i) a second browser implements a new API, or (ii) an API that failed to build consensus is removed by the one browser that implemented it.
This chart plots a count of APIs shipped by only one of the four browser vendors over time. Interacting with the chart on the dashboard lets you open the list of APIs that corresponds to each count:
This information helps browser vendors prioritize work that will make the web more interoperable by either removing old browser-specific APIs or working with other vendors to implement APIs that are not yet widely supported.

How APIs are collected

In order to count APIs on the web, we first had to define what counts as a “web API”. The web is full of useful features, some of which are hard to define let alone detect. For this analysis we focused on JavaScript APIs that are visible to the developer when the page first loads. This leaves out several classes of feature, like CSS properties, HTML attributes, and APIs that are not available on page load (e.g., APIs are surfaced through interaction user/API interactions, or only available in certain types of workers). Nevertheless, it gives us a general view of programmable browser capabilities.
Our JavaScript API-finding algorithm inspects the JavaScript object graph exposed on the global window object. Check out the link for details on how we managed to extract APIs from JavaScript prototypes. With the help of BrowserStack’s 1000+ browser/operating system configurations, we were able to gather API data for browser releases going back as far as 2012.
Determining if the web is healthy
Take a look at the metrics page on the dashboard and you’ll see a few different charts we’ve generated about the shape of the web. These metrics, and the APIs they represent, give web platform implementers insights into which APIs are fragmenting the web. APIs that fragment the web are:
  1. Shipped by almost every browser, but not quite;
  2. Removed by one browser, but not others; or
  3. Shipped by one browser, but not others.
For example, our data shows that Safari is the only major browser that does not ship CSSStyleDeclaration#backfaceVisibility, Chrome has removed a number of SVGSVGElement APIs that are still shipped by all major browsers, and Edge is the only major browser shipping a number of BhxBrowser APIs.

Querying the raw data yourself

The dashboard isn’t intended to replace tools like MDN Docs or, but rather to illustrate trends that help browser vendors keep evolving the web towards interoperability. That said, the catalog page on the dashboard can give developers another source to corroborate interop info from manually curated sources. Try playing around with the search box above the API catalog. It supports some basic structured queries like in:firefox60 or notin:chrome66 for APIs in Firefox 60 or missing from Chrome 66, or RTCPeerConnection count:2 for RTCPeerConnection-related APIs shipped by exactly two of the browsers currently in view. Clicking the vertical ellipsis icon lets you add or remove dozens of browser releases from the grid, and the URL bar always contains a link that will get you back to the current query.

Validating MDN browser compat tables

We’ve also started using the data to help tech writers programmatically check their contributions to MDN’s excellent browser compatibility database. Try this out:
# Clone MDN’s browser compatibility database
git clone
cd browser-compat-data
# Install dependencies
npm install
# Load confluence data for ServiceWorker
npm run confluence -- --interfaces=ServiceWorker
# Take a look at the differences that have been applied to your working tree
git diff
# Read the full list of parameters you can try on `npm run confluence`
npm run confluence -- --help


We hope both browser engineers and web developers can benefit from the dashboard. Check it out and let us know what you think over at the GitHub project that hosts the code.

Posted by Mark Dittmer, Software Engineer working on Web Ecosystem Infrastructure

Help test / provide feedback on upcoming Chrome browser features

Feeling adventurous? Preview upcoming Chrome features before they’re released across Desktop, Android and iOS.

What is the Chrome beta channel?
Chrome beta allows you to preview upcoming features before they’re released. You can expect weekly updates, access to features and designs that may or may not make it to a stable version, and the ability to submit feedback earlier in the development process.

How do I switch to the Chrome beta channel?

Is the beta channel considered stable enough to use every day?
Generally yes - but there may be hiccups along the way. We encourage beta channel users to regularly back up their important personal settings, like bookmarks, passwords, and more.

What’s the best way to provide feedback, report problems, etc.?
Chrome has three ways to provide feedback and report issues you may spot.
  1. Reporting feedback within Chrome. You can use the instructions found here to submit a feedback report within Chrome. We use these reports in aggregate to identify spikes and trends. We also perform deep dives when investigating issues, when checking in on new feature launches, and as part of regular user journey efforts.
  2. Troubleshooting an issue. Our official community forums are the best place to get help troubleshooting issues. We have a group of top contributors who also have the ability to escalate threads, which often help identify issues we aren’t seeing elsewhere.
  3. Reporting confirmed bugs on this project tracker. Once an issue is confirmed as a bug, you’re able to create a report to it on our public development tracker - straight to our team! You may find that your bug has already been reported (things move fast!), but this allows us to track a bug’s life cycle in an easy way.

Is there anything more beta than beta?
Yes! For some platforms, we also offer developer versions and even canary builds that are fresh off the test servers. These are generally only advised for folks that work on projects that need testing lead time. You can learn more about other release options here.

Chrome 69 Beta: CSS tricks, and more

Unless otherwise noted, changes described below apply to the newest Chrome Beta channel release for Android, Chrome OS, Linux, macOS, and Windows. View a complete list of the features in Chrome 69 on Chrome 69 is beta as of August 2.

New CSS tricks

Chrome has added several new CSS features.

Conic gradients

CSS conic (angular/sweep) gradients allow color transitions around a center rather than radiating from it. This allows, for example, creating a hue wheel using only two CSS properties as shown below. More examples are available.

div {
background: conic-gradient(red, yellow, lime, aqua, blue, magenta, red);
border-radius: 50%

New margin, padding, and border properties

Logical margin, padding, and border properties now use standard names, specifically margin-{block,inline}-{start,end}, padding-{block,inline}-{start,end} and border-{block,inline}-{start,end}-{width,style,color}. These capabilities were previously supported through -webkit prefixes and non-standard names. Shorthand properties are only added for border-{block,inline}-{start,end}.

CSS scroll snap

CSS scroll snap positions are offsets in a scroll container's visual viewport where scrolling will stop after each scrolling operation. This improves the user experience by allowing scrollable zones to easily stop at predefined points. This also enables common UX scroll patterns without the need for JavaScript. One such pattern is a horizontal image carousel accomplished with the declarations below. The article Well-Controlled Scrolling with CSS Scroll Snap provides more depth.

#gallery {
scroll-snap-type: x mandatory;
overflow-x: scroll;
display: flex;

#gallery img {
scroll-snap-align: center;

Display cutouts

Display cutouts are now supported in Chrome through the new CSS env() function (environment variables) and the viewport-fit meta tag. This allows developers to take advantage of the entire screen on devices that have a display cutout.

For example, to tell the browser to expand into the display cutout area the site should set the viewport-fit property in the viewport meta tag to cover. The site can then use the safe area inset CSS environment variables to layout their content without being covered by the cutout. This is shown below. The explainer and the spec provide more information.

<meta name="viewport" content="viewport-fit: cover" />

#box {
margin-top: env(safe-area-inset-top);
margin-left: env(safe-area-inset-left);
margin-bottom: env(safe-area-inset-bottom);
margin-right: env(safe-area-inset-right);

<div id=box></div>

Other features in this release


OffscreenCanvas is a new interface that allows 2D and WebGL canvas rendering contexts to be used in Workers. This increases parallelism in web applications and improves performance on multi-core systems.

Chrome now also supports DedicatedWorker.requestAnimationFrame(), allowing animation-like events to be triggered the same on dedicated workers as they are in Window. For example:

const offscreenCanvas = new OffscreenCanvas(100, 100);
const ctx = offscreenCanvas.getContext("2d");
ctx.fillRect(0, 0, 10, 10);

Or together with canvas:

const canvasElement = document.getElementById("mycanvas")
const offscreenCanvas = canvasElement.transferControlToOffscreen();
const ctx = offscreenCanvas.getContext("2d");
ctx.fillRect(0, 0, 10, 10);

Inside a worker:

self.onmessage = function(ev) {
const offscreenCanvas =;
const ctx = offscreenCanvas.getContext("2d");
let x = 0;
const draw = function() {
ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
ctx.fillRect(x, 0, 10, 10);
x = (x + 1) % ctx.canvas.width;

Main page:

const worker = new Worker("worker.js");
const offscreenCanvas =
worker.postMessage(offscreenCanvas, [offscreenCanvas]);


A new method named Element.toggleAttribute() allows toggling the existence of an element's attribute in a way similar to Element.classList.toggle. An optional force parameter forces addition or deletion of the attribute depending on the value of force. This makes managing boolean attributes much simpler as the interface doesn't use strings as does Element.setAttribute().

Fetch API: Request.isHistoryNavigation

A boolean property has been added to request objects to indicate whether a particular request is a history navigation. This allows a service worker to know whether a request was due to a back/forward navigation. An example of how this might be used is that a service worker could respond to such a navigation with a cached response.

JavaScript APIs

JavaScript has several new APIs:

Keyboard Map API

Some applications such as games assign specific functions to specific physical keys. When the interface references these keys it needs to show either the character displayed on the key, which varies by locale, or the character assigned to the key by an alternate keyboard layout that may have been installed by the user. Because of these layout variations it's sometimes possible for the character shown in the interface to not reference the intended physical key.
This new API provides a way to translate KeyboardEvent.code values representing physical keys into correct strings for display to the user. You can find details and examples of this new API in the specification and the explainer.


Support for the "rtt", "downlink", and "ect" client hint values and HTTP request headers have been added to Chrome to convey a device's network connection speed to servers. For example, the rtt client hint provides the server with the estimated effective round-trip time of the current connection, rounded to the nearest multiple of 25 milliseconds.The server could use this serve a downsampled image if the connection speed is slower than expected. These network quality hints provide to the server the same values as provided to a web page by the Network Information APIs navigator.connection.rtt, navigator.connection.downlink, and navigator.connection.effectiveType.

Media: Querying encryption scheme support through EME

Some platforms or key systems only support AES-128 in CTR mode, while others only support CBCS mode. Still others are able to support both. A new method allows web developers to query whether a specific encryption scheme is supported by Encrypted Media Extensions (EME).

Mid-ligature text selection

Chrome now allows for text to be selected inside ligatures. (A ligature is a combination of two or more letters in a single symbol.) This includes both mouse selection as well as cursor selection in input and textarea elements. We have also changed slightly the way we render text selection to support this change. Parts of text that happen to lie outside the selection area are now rendered with the original style:

Selection in a ligature in English.

Selection in a ligature in Arabic.


To avoid leaking information between frames, performance.memory values are currently heavily quantized, and delayed by 20 minutes.
If the renderer process is locked to documents from a single site (as in the case of Site Isolation on desktop), we can expose this information with fewer concerns about leaking information between frames. In these cases, we'll not return quantized memory consumption information, delayed by 30 seconds. This allows developers to detect performance regressions from user data more easily because the memory measurements will be more accurate and can be taken more frequently.


Service workers have two improvements:
. This aligns with the specification.

Update behavior of CSS Grid Layout percentage row tracks and gutters

In a future release there will be a change to how percentage row tracks and gutters are resolved on grid containers with indefinite height. Currently they behave similar to percentage heights in regular blocks, but going forward they will behave the same as for columns, making them symmetric.
Percentages will be ignored when computing intrinsic height (like it happens now) and resolved afterwards against that height. That way both column and row axes will have a symmetric behavior in order to resolve tracks and gutters specified by percentages.
In Chrome 69 you'll get a warning in the JavaScript console about this change. If you want to keep the current behavior in Chrome 70 you need to replace your percentage row tracks and gutters in indefinite height grid containers by "auto" and "0px" respectively.

Web Locks API

The Web Locks API allows scripts running in one tab to asynchronously acquire a lock, hold it while work is performed, then release it. While held, no other script executing in the same origin can acquire the same lock. A lock represents some potentially shared resource, identified by a name chosen by the web app. For example, if a web app running in multiple tabs wants to ensure that only one tab is syncing to the network, each tab could try to acquire a my_net_sync lock, but only one tab will succeed.
An example is shown below. It shows a function called when a lock for my_resource is acquired.

await navigator.locks.request('my_resource', async lock => {
const url = await look_up_in_database();
const response = await fetch(url);
const body = await response.text();
await store_body_in_database(body);

For more details about the API methods and options, see the explainer and draft specification.

Web Authentication now supports CTAP2 FIDO devices

Web Authentication adds support for CTAP2 devices, which provide advanced security capabilities such as biometric authentication and resident keys (keys stored on the device). The WebAuthentication API formerly only supported Universal 2nd Factor (U2F) devices at the transport layer. This change doesn't alter the API surface itself, but enables richer device interactions via the existing Web Authentication API.


WebRTC has two improvements:
which returns the most optimistic view of the capabilities of the system for sending media of the given kind. It does not reserve any resources, ports, or other state but is meant to provide a way to discover the types of capabilities of the browser including which codecs or RTP extensions may be supported.

Deprecations and Interoperability Improvements

Chrome sometimes deprecates, removes, or changes features to increase interoperability with other browsers. This version of Chrome includes the following such changes.

Removal of 'stalled' event from HTMLMediaElements that use Media Source Extensions

Previously, the HTMLMediaElement.stalled event fired when media download has failed to progress for at least 3 seconds. In Media Source Extensions, the web app manages the download and the media element is not aware of its progress. Since some apps append media data in chunks larger than 3 seconds, stalled was being fired at inappropriate times. To solve this, stalled has been removed for Media Source Extensions.

Removal of document.createTouchList

The document.createTouchList() method was removed
in favor of the Touch() constructor which has been supported since Chrome 48.

The window.confirm() method no longer activates its parent tab

If a document in a background tab calls window.confirm(), it returns immediately with false, and no dialog is shown to the user. If the tab is active, then the call shows a dialog as normal. Specifically, this removes the ability to use window.confirm() to bring a tab to the front because this is rarely what the user wants.

Bringing Google Pay to PaymentRequest

In September 2016 Chrome launched support for the PaymentRequest API, which offers a secure, seamless checkout experience built right into the browser. As part of that launch, Chrome offered support for the basic-card payment method. This allowed users to pay for goods online via PaymentRequest with credit or debit cards stored locally in Chrome or, for signed-in users, stored within their Google Account.

As of version 70, Chrome will no longer return cards stored in a user’s Google Account as part of the basic-card payment method. To continue getting access to cards stored in a user’s Google Account, developers will need to add support for Google Pay. This change is due to the fact that beginning with version 68, Chrome supports the Payment Handler API, a standards-based way for the browser to communicate with digital payment providers. Google Pay supports this standard.

Getting started with Google Pay is easy. Visit the developer site for a quick tutorial and review the latest Google Pay brand guidelines for best practices. When you are ready to implement, just follow the detailed checklist to test your integration and request production access.

You can find troubleshooting tips for common issues and can contact the Google Pay team if you need any additional help. Thanks for helping us make payments on the web a great experience for users everywhere.

Posted by Zach Koch, Product Manager

Improving extension transparency for users

We strive to ensure choice and transparency for all Chrome users as they browse the web. Part of this choice is the ability to use the hundreds of thousands of extensions available in the Chrome Web Store to customize the browsing experience in useful and productivity-boosting ways. However, we continue to receive large volumes of complaints from users about unwanted extensions causing their Chrome experience to change unexpectedly — and the majority of these complaints are attributed to confusing or deceptive uses of inline installation on websites. As we’ve attempted to address this problem over the past few years, we’ve learned that the information displayed alongside extensions in the Chrome Web Store plays a critical role in ensuring that users can make informed decisions about whether to install an extension. When installed through the Chrome Web Store, extensions are significantly less likely to be uninstalled or cause user complaints, compared to extensions installed through inline installation.

Later this summer, inline installation will be retired on all platforms. Going forward, users will only be able to install extensions from within the Chrome Web Store, where they can view all information about an extension’s functionality prior to installing.

This change will roll out in three phases:

  • Starting today, inline installation will be unavailable to all newly published extensions. Extensions first published on June 12, 2018 or later that attempt to call the chrome.webstore.install() function will automatically redirect the user to the Chrome Web Store in a new tab to complete the installation.
  • Starting September 12, 2018, inline installation will be disabled for existing extensions, and users will be automatically redirected to the Chrome Web Store to complete the installation.
  • In early December 2018, the inline install API method will be removed from Chrome 71.

If you distribute an extension using inline installation, you will need to update install buttons on your website to link to your extension’s Chrome Web Store page prior to the stable release of Chrome 71. And if you haven’t already, be sure to read up on how to create a high quality store listing, and consider using our install badge on your site.

We’re proud of the choices the Chrome Web Store provides users in enhancing their browsing experience. At the same time, it’s crucial that users have robust information about extensions prior to installation, so that they fully understand how their browsing experience will be impacted. We’re confident this change will improve transparency for all users about their extension choices in Chrome.

Posted by James Wagner, Extensions Platform Product Manager

Chrome 68 Beta: add to home screen, payment handler, page lifecycle

Unless otherwise noted, changes described below apply to the newest Chrome Beta channel release for Android, Chrome OS, Linux, macOS, and Windows. View a complete list of the features in Chrome 68 on Chrome 68 is beta as of June 7, 2018.

New add to home screen behavior for progressive web apps

We've heard from developers that they want more control over how and when the add to home screen prompt appears. Starting in Chrome 68 on Android, the behavior is changing to provide more control over when the prompt appears. Developers can now provide additional context for their add to home screen experience, and improve the click-through rate.
Add to home screen dialog

If a site meets the add to home screen criteria, Chrome will fire a beforeinstallprompt event, and no longer automatically show the add to home screen banner. Instead, when the event has fired, developers can save the event and add a button or other UI element to the app to indicate it can be installed. When the user clicks the install button, developers can call prompt() on the saved beforeinstallprompt event to show the new add to home screen modal dialog. Although the beforeinstallprompt event may be fired without a user gesture, calling prompt() requires one.

let installPromptEvent;

window.addEventListener('beforeinstallprompt', (event) => {
// Prevent Chrome <= 67 from automatically showing the prompt
// Stash the event so it can be triggered later.
installPromptEvent = event;
// Update UI notify the user they can add to home screen
document.querySelector('#install-button').disabled = false;

As a temporary measure to provide developers with time to handle the beforeinstallpromptevent and add an install button to their app, Chrome will show a mini-infobar the first time the user visits a site that meets the add to home screen criteria. Once dismissed, the mini-infobar will not be shown again until a sufficient amount of time (currently 3 months) has passed.
Add to home screen mini infobar

See Changes to add home screen behavior for complete details, code samples and screenshots of the new UI elements.

Payment Handler API

The Payment Request API brought the web a simpler, faster way to check out online by combining a seamless native-browser UI with a user's preferred form of payment and shipping addresses.

The just-launched Payment Handler API extends the reach of Payment Request by enabling web-based payment apps to facilitate payments directly within the Payment Request experience.

const request = new PaymentRequest([{
// Your custom payment method identifier comes here
supportedMethods: ''
}], {
total: {
label: 'total',
amount: { value: '10', currency: 'USD' }

Making a payment through the Payment Request API. "Pay with BobPay" is a custom payment method built with the Payment Handler API.

Protecting users from unwanted destinations

In this version of Chrome we are changing a few user interface behaviors to improve users' experience.

Require user gesture for redirects in cross-origin iframes

Unless forbidden by the sandbox attribute, content embedded in an iframe can generally navigate the top-level browsing context to a different website. This functionality is used by many types of websites, including single-sign-on providers and payment processors. Unfortunately, this behavior is also a common abuse vector, redirecting users to unwanted destinations without their knowledge or consent.

Beginning in Chrome 68, content embedded in an iframe will require a user gesture to navigate the top-level browsing context to a different origin. Similar to pop-up blocking, when this protection triggers users will see Chrome UI giving them the option to allow the redirect the continue.

A demonstration illustrates the behavior. The demo behind this link will exhibit the old behavior in Chrome 67 and early. The improved behavior works in Chrome 68.

Block tab-under navigations

A tab-under is when a page both opens a popup to some destination and navigates the opener page to some third-party content. Typically this behavior is used to send the user to a desired destination while also creating another tab with an unwanted destination. Similar to pop-ups, Chrome will prevent these unwanted navigations and instead show native UI to the user so they can choose whether to follow this redirect to the new direction.

The Page Lifecycle API

Application lifecycle is a key way that modern operating systems manage resources. On Android, iOS and recently Windows, apps can be started and stopped at any time by the platform. This allows these platforms to streamline and reallocate resources where they best benefit the user.

On the web, there has historically been no such lifecycle, and apps can be alive indefinitely. With large numbers of web apps (and tabs) running, critical resources such as memory, CPU, battery, and network can be oversubscribed, leading to a bad end-user experience.

In Chrome 68, developers will be able to listen for and respond to system-initiated CPU suspension of backgrounded tabs using the new freeze and resume events. In cases where a frozen page needs to be discarded to conserve memory, the document.wasDiscarded property is now available so developers can restore view state (saved in the freeze event) when the user refocuses the tab and the page is reloaded. Developers wanting to test these events in their own applications can visit chrome://discards to simulate page freezing, resuming, and discarding.

For more information on the Page Lifecycle API, refer to the specification or the explainer on GitHub.

Other features in this release


Accept two values in the overflow shorthand

The overflow shorthand will accept two values, making it possible to set the horizontal and vertical overflow to different values. If two values are specified, the first is overflow-x and the second is overflow-y. Changing the shorthand allows developers to specify a single statement where previously two were required.

CSS position values with three parts

The object-position and perspective-origin properties will no longer accept three-part values like "top right 20%". This also applies for positions in basic shapes and gradients. Valid position values will now always have 1, 2 or 4 parts. Deprecation of 3-part values occurred in Chrome 66.

Support 'x' as a resolution unit

CSS Values and Units Module Level 4 defines a new resolution unit called "dot per pixel" for support of high-resolution displays. This change adds 'x' as a synonym for the existing abbreviation, 'dppx'.

Unprefix CSS "grab" and "grabbing" values for cursor property

The CSS values "grab" and "grabbing" change the mouse cursor to an open hand or closed hand, commonly used to indicate that something can be grabbed or is currently grabbed. Prefixed versions of these properties have been supported since Chrome 1. With this change Chrome will support the standard, unprefixed versions of these values.


High resolution timestamp for Gamepad

Gamepad.timestamp now uses a DOMHighResTimeStamp, a high resolution monotonic time with microsecond resolution. Timestamps are measured as offsets from the PerformanceTiming.navigationStart property.

Custom elements

New customElements.upgrade()

This function invokes custom element constructors for custom elements whose constructors are not called yet explicitly. If a custom element is created with the innerHTML setter and its parent node is not connected to a document, the custom element constructor is not called until it's connected. This method explicitly allows developers to fully control the timing of custom element constructor calls regardless of connectedness.


Keyboard lock

While in fullscreen, this API allows apps to receive keys that are normally handled by the system or the browser like Cmd-Tab/Alt-Tab, or Esc. Users can escape keyboard lock (and fullscreen) by holding the Esc key for two seconds.

Make PointerEvent.fromElement and PointerEvent.toElement null

To improve consistency with other browsers, PointerEvents for fromElement and toElement fields not follow the Pointer Events Level 2 spec by always reporting null.
In a MouseEvent (from which a PointerEvent inherits these fields), fromElement and toElement are non-standard, and have been inconsistent among major browsers for many years. Moreover, there are standard and consistent alternatives already: target and relatedTarget.

Unified touch adjustment

Touch adjustment changes the TouchEvent and the corresponding PointerEvent target to a best target within the touch area. TouchEvent coordinates will not be changed.

Treat long-press as a user gesture

Long-press is now considered a user gesture because it indicates user interaction with the page. This allows a web app to call restricted APIs like navigator.vibrate() on long-press to match native behavior.


WebAudio: add user selectable automation rate for AudioParams

The AudioParam.automationRate
attribute allows the user to select whether the AudioParam is either "a-rate" or "k-rate". Most but not all AudioParam attributes allow changing the rate, as given in the spec.
For example, BiquadFilterNode with default "a-rate" automation is expensive to compute due to the complex relationship between the parameters and the filter coefficients. If this fast automation is not needed (the most typical case), the parameters can be set to "k-rate".


Improve cache management for service worker scripts

The HTTP cache will be ignored when requesting updates to the service worker. Requests for importScripts will still go through the HTTP cache. But this is just the default. A new registration option, ServiceWorkerRegistration.updateViaCache is available that offers control over this behavior.
Previously, HTTP requests that checked for updates to the service worker were fulfilled by the HTTP cache by default. If a Cache-Control header was inadvertently set on a service worker, then service worker updates could be delayed, and if your service worker contained versioning information for your sites other assets, those updates would also be delayed.


RTCRtpSender.getParameters()/setParameters() return and control track encoding

The getParameters() and setParameters() methods return or update the RTCRtpSender object's current parameters for how the RTCRtpSender.track property is encoded and transmitted to a remote RTCRtpReceiver. These methods enable you to change encoding parameters for WebRTC streams such as the maximum transmission bitrate without doing any SDP munging or renegotiation.

Deprecations and interoperability improvements

Chrome sometimes deprecates, removes, or changes features to increase interoperability with other browsers. This version of Chrome includes the following such changes.

Deprecate and remove negative brightness values in filter

For compliance with specification, filter's brightness() function no longer accepts negative values.

Remove document.createTouch

The document.createTouch() method is being removed because the Touch() constructor has been supported since Chrome 48.

Remove Document.selectedStylesheetSet and Document.preferredStylesheetSet

The Document.selectedStylesheetSet and Document.preferredStylesheetSet attributes are removed because they are non-standard and only implemented by Chrome and WebKit. The standard versions of these attributes were removed from the spec in 2016.


Previously, Chrome provided the AMD_compressed_ATC_texture formats. Hardware support has dwindled to near-zero, so the extension has been rejected by the WebGL Working Group. Support for it has been removed.

Evolving Chrome's security indicators

Previously, we posted a proposal to mark all HTTP pages as definitively “not secure” and remove secure indicators for HTTPS pages. HTTPS usage on the web has taken off as we’ve evolved Chrome security indicators. Later this year, we’ll be taking several more steps along this path.

Users should expect that the web is safe by default, and they’ll be warned when there’s an issue. Since we’ll soon start marking all HTTP pages as “not secure”, we’ll step towards removing Chrome’s positive security indicators so that the default unmarked state is secure. Chrome will roll this out over time, starting by removing the “Secure” wording and HTTPS scheme in September 2018 (Chrome 69).

Chrome treatment for HTTPS pages

Previously, HTTP usage was too high to mark all HTTP pages with a strong red warning, but in October 2018 (Chrome 70), we’ll start showing the red “not secure” warning when users enter data on HTTP pages.

Chrome 70 treatment for HTTP pages with user input

We hope these changes continue to pave the way for a web that’s easy to use safely, by default. HTTPS is cheaper and easier than ever before, and unlocks powerful capabilities -- so don’t wait to migrate to HTTPS! Check out our set-up guides to get started.

Posted by Emily Schechter, Product Manager, Chrome Security

The State of the Web at Google I/O 2018

The web is a global treasure, and has many strengths we all enjoy. It is a distribution platform like no other, providing people around the world access to a diverse range of content and enabling businesses to reach customers wherever they are. Underpinning the web’s success is its community and a set of fundamentally open standards, which ensures it remains dynamic and available to all.

From PageRank to Chromium, Google has been deeply invested in the web’s continued success. This week at Google I/O, our annual developer conference, we gave a State of the Union presentation to catalog some of our recent efforts to help the web continue to thrive and work well for everyone. We recap the key themes below, but encourage you to check out all the talks on YouTube.

Service Worker
The introduction of the Service Worker API is one of the most significant improvements to the web in recent history. It frees developers from the limited lifecycle of pages, working in the background to intercept network requests and handle incoming events to enable web apps to work offline. With service workers your site can receive push notifications, synchronize data in the background, and more. Apple rolled out support for service workers in Safari 11.1 on iOS and MacOS this March and Microsoft Edge shipped service workers just last week — meaning that every major modern browser now supports the standard. Using service workers can be a big change to your architecture, so to make it simpler we created Workbox, which wraps up many common, powerful service worker patterns into an easy-to-use API. We've just released version 3 of this library, built around modules allowing you to use only the features that you need.

Progressive Web Apps (PWAs)
Service workers provide the backbone for many of the capabilities of a PWA. Companies around the world, in many different industries, have been seeing incredible success building PWAs. Starbucks, who launched their PWA site last year, saw a 2X increase in their daily active users. In fact, across advertising sites that we measured, when a site switches to a PWA they see on average a mobile conversion rate boost of 20%.

Many early PWAs were focused on mobile, and the benefits now also extend to desktop. Chrome will soon provide support for users to “install” PWAs to their desktop. The site will get its own icon and launch in a standalone window, while retaining powerful features that one expects in a browser like find in page, shareable URLs, Google Cast support, and more. At I/O we demonstrated how Spotify is deploying their rich media experience as a desktop PWA. “Install” support for desktop PWA’s will be coming to ChromeOS in Chrome 67 in early June, and on Windows and macOS later this year.

WebAssembly enables websites to run high-performance, low-level code written in languages like C or C++, and opens up entirely new classes of content on the web platform. In March, AutoCAD from Autodesk took a 35-year-old-codebase — older than the web itself — and compiled it to run directly inside a browser using WebAssembly. AutoCAD is now just a link away, meaning you can make edits to your CAD drawing directly in a browser, regardless of device or operating system. AutoCAD’s engineering team has a single shared C++ codebase, and when their desktop team makes changes, they are easily integrated into the AutoCAD web app.

If you’re interested in learning how to port code or write your own, check out the WebAssembly codelab, demonstrating the interplay between C libraries and the DOM. Whether you’re using a complex library written in C, want to bring a new codec into the web platform, or using an engine such as Unity or Unreal Engine, WebAssembly is here to help.

Lighthouse is a tool for analyzing the quality of your website, giving you clear measurements of your site’s performance and guidance for improving your users’ experience. It can be accessed directly from inside Chrome’s DevTools, run from the command-line, or integrated with other development products. In 2018 alone, half a million developers are running Lighthouse against their sites on a regular basis. We know that the web changes fast — Lighthouse can help you stay up-to-date with the latest performance best-practices. Lighthouse 3.0, announced at I/O, will be available to everyone later this week.

Lighthouse gives you clarity into your site’s load performance in a controlled environment. However, if you want to see how your site performs for real users in the real world, then check out the Chrome User Experience Report. The report now provides origin-level performance metrics for the four million most visited websites. To learn more about how these and other tools can help you get a complete view of your site’s performance, check out our speed tools infographic.

AMP is a web component library and ecosystem for building reliably fast websites with great user experience at scale. There are now over six billion AMP pages from 46 million domains, with a median load time of less than one second from Google Search. Businesses are seeing success with AMP: AliExpress, the global online retail marketplace, recently launched a new mobile site as an AMP-driven Progressive Web App. The new site increased their conversion rate for non-search traffic by an incredible 31%.

Content consumption on mobile is changing, with bite-sized, fullscreen storytelling formats becoming increasingly popular. To help meet the needs of web publishers, the AMP project recently announced the development of AMP stories, a rich set of web components built for mobile-first storytelling. The format is under continued development, and we encourage you to experiment with building your own stories and give the AMP team your feedback.

Web Packaging
Web Packaging is a set of emerging technologies that we believe will redefine how web content is distributed on the web and shared between users. It allows publishers to bundle their content for distribution by other parties, while keeping the integrity guarantees of HTTPS. As part of exploring the novel use cases enabled by Web Packaging, we realized that there was an interesting opportunity for AMP. Through collaboration with the AMP team and the web community, we were able to design a solution that allows AMP documents to retain the publisher's original URL when served from the AMP cache.

As a showcase of our efforts, AMP project collaborators Food Network and Pinterest have built demos of Web Packaging, such as the one below. If you are curious to learn more, the AMP team wrote an article that goes into more detail about how Web Packaging benefits users and publishers. Beyond the AMP application, we are excited about what Web Packaging technologies will enable and are looking forward to refine our thinking with your help.

A demo using Web Packaging with an AMP page from Google Search

Polymer is a JavaScript library that helps you create custom reusable web components to share with other developers or combine to build performant, maintainable apps. At I/O we launched version 3.0 of the library, which makes some significant upgrades to the Polymer ecosystem. We’ve completed support for using npm as the package management system and ES6 modules as the unit of composition, making it easy to use Polymer-based web components alongside your other favorite web development tools and frameworks.

We’ve also introduced LitElement, a new web component base-class that combines the expressive power of Lit-HTML with web components to make it even easier to create lightweight, reactive components using a modern and expressive templating syntax.

We’re also releasing the PWA Starter Kit, a comprehensive starting point for building web component-driven PWAs that are fast, reliable, responsive, themable, and score top marks in our Lighthouse PWA and performance criteria.

At I/O this year the Angular team gave an overview of the growth of the community, and touched on some of the exciting new capabilities that have landed across the core framework, CLI, and Angular Material library in version 6. Angular is used by millions of developers and has built up a huge amount of momentum and a fantastic ecosystem. New commands released in version 6 like `ng update` and `ng add` will keep your application up to date and help developers move faster as the Angular team continues to balance stability and innovation.

The Angular team also gave a sneak peek at some of the improvements they are making under the hood of Angular with Project Ivy. This will make Angular simpler to debug and faster to compile and run, in a way that works with existing applications. The team showed demonstrated the utility of these improvements in the form of a small Hello World application where the Angular features that weren't used were automatically removed from the application's JavaScript bundle.

Our mission at Google and in Chrome is to work with the community to create experiences that are fast, integrated, reliable, and engaging. We’re excited by the powerful new capabilities that have come to the open web platform, and the comprehensive set of tools that enable you to rapidly build high quality sites for your users. To stay up to date on the latest advancements in the web, visit our developer portal or check out the talks from this year’s I/O on the Google Developers YouTube channel. And we’d love to see you at the upcoming Chrome Dev Summit later this year.

Posted by Malte Ubl and Ben Galbraith

Chrome 67 Beta: WebXR Origin Trial, and Generic Sensors

Unless otherwise noted, changes described below apply to the newest Chrome Beta channel release for Android, Chrome OS, Linux, macOS, and Windows. View a complete list of the features in Chrome 67 on

Generic Sensors

Sensor data is used in many native applications to enable experiences like immersive gaming, fitness tracking, and augmented or virtual reality. This data is now available to web applications using the Generic Sensor API. The API consists of a base Sensor interface with a set of concrete sensor classes built on top. Here are links to the sensor specs and examples of how they might be used.

Accelerometer: Use the motion of the device to move around in a 3D video.

Gyroscope: Use the orientation of the device to implement a table-top maze.

Orientation Sensor: This is what's called a fusion sensor meaning it combines readings from two or more sensors, in this case the accelerometer and the gyroscope. Whereas a maze implemented using only the gyroscope might only move the location marker in two dimensions, one implemented with the orientation sensor could require the user to physically turn the device to turn a corner.

Motion Sensors: This is a fusion sensor that includes a magnetometer as well as the accelerometer and the gyroscope. The most obvious use case for this as a virtual compass.

Accelerometer sensor measurements provide the movement speed of the device in terms of x, y, and z coordinates.

Intel has a website devoted to demonstrations of the sensor APIs with sample code available for download. The article published at the start of the origin trial has been updated.

WebXR Device API Origin Trial

The WebXR Device API enables the creation of virtual and augmented reality experiences on mobile devices and desktops - unifying experiences across AR enabled mobile devices, mobile-based VR headsets like Google Daydream View and Samsung Gear VR, as well as desktop-hosted headsets like Oculus Rift, HTC Vive, and Windows Mixed Reality Headsets.

The new API is available as an origin trial (explainer, sign-up form). You can find samples and documentation in the Immersive Web Community Group GitHub repos. There's also a polyfill available that supports browsers with WebVR 1.1 support, browsers without support, and "magic window" on mobile devices.

Watching a video in virtual reality

Virtual and augmented reality experiences enabled by this API include games as well as other "long tail" applications, such as:
Note: If you are participating in the WebVR origin Trial that has been available in Chrome since version 62, you cannot use your existing token for the WebXR origin Trial. The WebVR origin Trial (the old one) previously set to end on July 24, 2018, has been extended to September.

Other Features in this Release


SVG2 requires <foreignObject> to be a stacking context. Making <foreignObject> a stacking context allows developers to place HTML content underneath a <foreignObject> without confusion.


The DOM specification was updated so that DOMTokenList.replace() returns a boolean value indicating whether a replacement occurred. This is useful for code that takes different paths depending on whether a replacement occurred, avoiding the need for an extra condition using contains(). Chrome now follows the specification.

HTML > CustomElements

Authors can now create custom elements that inherit from the semantics of native, built-in elements. This saves developers from reimplementing built-in functionality such as accessibility, semantics, JavaScript methods/properties.


Web pages can now process mouse events (mousedown, auxclick, mouseup) for back and forward buttons on mice with five or more buttons. This allows back and forward mouse buttons to be prevented by applications such as games that wish to override them.

On Windows the right-hand Alt key serves as AltGraph (ISO-Level-3-Shift) on some layouts, such as many European language layouts, to allow generating additional printable-characters. Internally the key generates Ctrl+Alt modifiers, so that Chrome reports all of Control, Alt and AltGraph in the flags for these keys. In this change, Chrome distinguishes AltGraph from Ctrl+Alt under Windows for consistency with these modifiers on other platforms.

For developers this removes an edge-case from keyboard event modifier handling. If an app handles keydown/keypress/keyup to implement shortcuts, it will no longer need workarounds to cope with certain (mainly European) keyboard layouts. For example, if an app uses Ctrl+# as a shortcut (as GMail did) then previously the app would need to check for both Ctrl, and for AltGraph, otherwise French users would not be able to use it.
This change applies to Windows only.


JavaScript now has a numeric primitive that provides support for arbitrary precision integers. Previously, numbers in JavaScript were represented as double-precision floats, giving them limited precision. Using the BigInt() function and 'n' suffix on numeric literals you can safely store and operate on large integers even beyond the safe integer limit for numbers.


Formatting contexts will now behave exactly like floats do when they are positioned. In other words, they no longer look at the shape-outside property of the float for positioning and instead are positioned according to their margin box. The new behavior may be seen in this example by changing the height of the flex class. This also affects how new formatting contexts are sized and positioned.


Client Hints enable origins to receive device-specific preferences in the HTTP request headers. Accept-CH-Lifetime adds a client hint that allow origins to persist their opt-in policy for a specified period so they can receive client hints on navigation requests. Additionally, on the first page load, this feature provides hints for all subresources of the page.

Network > Streams API

TransformStream is part of the Streams API, which is used for creating, composing, and consuming streams of data. It enables transforming data in stream form. It is typically used in a pipe between a ReadableStream and a WritableStream. The following example uses TransformStream to decode text received in a streaming response body.

function textDecodeTransform() {
const decoder = new TextDecoder();
return new TransformStream({
transform(chunk, controller) {
controller.enqueue(decoder.decode(chunk, { stream: true }));

fetch(url).then(response => {
// response.body is a stream of Uint8Array chunks.
// But if we want chunks of text:
const stream = response.body.pipeThrough(textDecodeTransform());
// …

Shadow DOM

The <slot> element can now participate in a flat layout tree, with UA style display: contents. Before this change, applying a CSS selector to a <slot> element had no effect. Not only is this fixed, but when selectors are applied to a <slot> element, its children inherit its styles.

Deprecations and Interoperability Improvements

Chrome sometimes deprecates, removes, or changes features to increase interoperability with other browsers. This version of Chrome includes the following such changes.

Deprecate HTTP-Based Public Key Pinning

HTTP-Based Public Key Pinning (HPKP) was intended to allow websites to send an HTTP header that pins one or more of the public keys present in the site's certificate chain. It has very low adoption, and although it provides security against certificate mis-issuance, it also creates risks of denial of service and hostile pinning.

To defend against certificate misissuance, web developers should use the Expect-CT header, including its reporting function. Expect-CT is safer than HPKP due to the flexibility it gives site operators to recover from configuration errors, and due to the built-in support offered by a number of CAs.

We expect to remove this in Chrome 69.

Deprecate AppCache on Non-secure Contexts

AppCache over HTTP is deprecated. AppCache is a powerful feature that allows offline and persistent access to an origin. Allowing AppCache to be used over non-secure contexts makes it an attack vector for cross-site scripting hacks.
Removal is expected in Chrome 69.


Several Webkit-prefixed CSS properties will be removed in this release.

-webkit-box-flex-group: This property has minimal usage based on the UseCounter in stable.

Percent (%) values for -webkit-line-clamp: There is interest in finding a standards-based solution to the number values use case, but we haven't seen demand for the %-based values.

-webkit-box-lines: This property was never fully implemented. It was originally intended such that a "vertical"/"horizontal" -webkit-box could have multiple rows/columns.

Protecting WebView with Safe Browsing

Since 2007, Google Safe Browsing has been protecting users across the web from phishing and malware attacks. It protects over three billion devices from an increasing number of threats, now also including unwanted software across desktop and mobile platforms. Today, we’re announcing that Google Play Protect is bringing Safe Browsing to WebView by default, starting in April 2018 with the release of WebView 66.

Developers of Android apps using WebView no longer have to make any changes to benefit from this protection. Safe Browsing in WebView has been available since Android 8.0 (API level 26), using the same underlying technology as Chrome on Android. When Safe Browsing is triggered, the app will present a warning and receive a network error. Apps built for API level 27 and above can customize this behavior with new APIs for Safe Browsing.

An example of a warning shown when Safe Browsing detects a dangerous site. The style and content of the warning will vary depending on the size of the WebView.

You can learn more about customizing and controlling Safe Browsing in the Android API documentation, and you can test your application today by visiting the Safe Browsing test URL (chrome://safe-browsing/match?type=malware) while using the current WebView beta.

Posted by Nate Fischer, Software Engineer

Protecting users from extension cryptojacking

As the extensions ecosystem continues to evolve, we remain focused on empowering developers to build innovative experiences while keeping our users as safe as possible. Over the past few months, there has been a rise in malicious extensions that appear to provide useful functionality on the surface, while embedding hidden cryptocurrency mining scripts that run in the background without the user’s consent. These mining scripts often consume significant CPU resources, and can severely impact system performance and power consumption.

 The chart above shows a recent example of CPU overutilization from hidden coin mining in an extension. 
Until now, Chrome Web Store policy has permitted cryptocurrency mining in extensions as long as it is the extension’s single purpose, and the user is adequately informed about the mining behavior. Unfortunately, approximately 90% of all extensions with mining scripts that developers have attempted to upload to Chrome Web Store have failed to comply with these policies, and have been either rejected or removed from the store.

Starting today, Chrome Web Store will no longer accept extensions that mine cryptocurrency. Existing extensions that mine cryptocurrency will be delisted from the Chrome Web Store in late June. Extensions with blockchain-related purposes other than mining will continue to be permitted in the Web Store.

The extensions platform provides powerful capabilities that have enabled our developer community to build a vibrant catalog of extensions that help users get the most out of Chrome. Unfortunately, these same capabilities have attracted malicious software developers who attempt to abuse the platform at the expense of users. This policy is another step forward in ensuring that Chrome users can enjoy the benefits of extensions without exposing themselves to hidden risks.

Posted by James Wagner, Extensions Platform Product Manager

Chrome 66 Beta: CSS Typed Object Model, Async Clipboard API, AudioWorklet

Unless otherwise noted, changes described below apply to the newest Chrome Beta channel release for Android, Chrome OS, Linux, macOS, and Windows. View a complete list of the features in Chrome 66 on ChromeStatus.

The ImageBitmap Rendering Context for <canvas>

Historically, rendering an image to a canvas has involved first creating an <img> tag and then rendering its contents to a canvas. This causes multiple copies of the image to be stored in memory. A new rendering context streamlines the display of ImageBitmap objects by avoiding memory duplication and rendering them more efficiently.
This example shows how to do this using an ImageBitmapRenderingContext. This essentially transfers ownership of an image's pixels. This example does so from a blob to a <canvas>, but pixels can be moved between <canvas> elements as well. Note that the blob is compressed so it is not a full copy in memory.

const image = await createImageBitmap(imageBlob);
const canvas = document.createElement('canvas');
const context = canvas.getContext('bitmaprenderer');

canvas.toBlob((outputJPEGBlob) => {
// Do something with outputJPEGBlob.
}, 'image/jpeg');

If this were done without createImageBitmap(), the imageBlob would be lazily decoded, which would cause jank. On the other hand createImageBitmap() is asynchronous which allows you to decode it completely before using it and avoiding jank. For example, a WebGL game could use this to load new textures on the fly as gameplay progresses.

CSS Typed Object Model

Historically, developers wanting to manipulate CSS properties have had to manipulate strings only for the browser to then convert it back to a typed representation. What made things worse was when developers tried to read the value of a CSS property in Javascript, this typed value was converted back to a string.
In version 66, Chrome implements the CSS Typed Object Model (OM) Level 1, a part of Houdini, for a subset of CSS properties. Typed OM reduces this burden on both the developer and browser by exposing CSS values as typed JavaScript objects rather than strings. Along with allowing the performant manipulation of values assigned to CSS properties, Typed OM allows developers to write more maintainable and easy to understand code.
A brief example illustrates the point. Previously if I wanted to set the opacity of an element I could do this: = 0.3; === "0.3"


el.attributeStyleMap.set("opacity", CSS.number("0.3"));
el.attributeStyleMap.get("opacity").value === 0.3

The returned values above are of type CSSUnitValue, which are easier to manipulate than strings.

Asynchronous Clipboard API

The new asynchronous clipboard API provides a promise-based means of reading from and writing to the clipboard. It's simpler than the old execCommand('copy') API released in Chrome 43 and integrates with the Permissions API. Future Chrome releases will also support copy/paste of richer types of data, including images.
To get a taste of this API, lets do simple write and read operations with text.

try {
await navigator.clipboard.writeText("Hello, clipboard.");
} catch {
console.error("Unable to write to clipboard.");

Similarly, to read text back:

const data = await navigator.clipboard.readText();
console.log("From the clipboard:", data);

For more information, including how to use security and permissions with the API, read Unblocking Clipboard Access and check out our sample.


The legacy ScriptProcessorNode was asynchronous and required thread hops, which could produce an unstable audio output. The AudioWorklet object provides a new synchronous JavaScript execution context which allows developers to programmatically control audio without additional latency and higher stability in the output audio.
You can see example code in action along with other examples at Google Chrome Labs.
In addition to AudioWorklet, other worklet API are being built. PaintWorklet was released in Chrome 65/Opera 52. An AnimationWorklet is planned. ScriptProcessorNode will be deprecated some time after AudioWorklet ships.

Other Features in this Release

Blink > Animation

The add and accumulate compositing operations are intended for building modularized animations. The add and accumulate keywords will be supported in Chrome soon. Until then, they will no longer throw errors. This is to maintain compatibility with Firefox and other implementations.

Blink > CSS

CSS has two new features.

Blink > Feature Policy

By default, the deviceorientation, deviceorientationabsolute, and devicemotion events are now restricted to top-level document and same-origin subframes, the same as if the feature policy for those features were set to 'self'. To modify this behavior, explicitly enable or disable the specific feature.

Blink > File API

The File API now results in a network error instead of a 404 when attempting to read from an invalid or non-existing blob URL.

Blink > Forms

HTML forms have two new features.

Blink > Fullscreen

If a page in fullscreen mode opens a popup and calls window.focus(), that page exits full screen. This does not occur if the popup receives focus some other way.

Blink > GetUserMedia

A new method on the MediaStreamTrack interface called getCapabilities()
returns a MediaTrackCapabilities object, which specifies the values or range of values which each constrianable property. Capabilities vary by device.

Blink > JavaScript

There are several JavaScript changes.

Blink > Layout

Layout has two new features.
The default value for all three is normal and the prefixed properties are aliases of the new ones. Note that column-gap property already exists and is used by css-multicol.

Blink > Media

Media has two new features.

Blink > Network

The Fetch API has two new features.

const controller = new AbortController();
const signal = controller.signal;
const requestPromise = fetch(url, { signal });

// Abort the fetch:

Blink > ServiceWorker

Service workers have two changes.

Blink > WebRTC

Chrome now supports the RTCRtpSender.dtmf
attribute per the specification. This replaces the CreateDTMFSender() function which has not yet been deprecated.

Deprecations and Interoperability Improvements

Blink > CSS

The object-position and perspective-origin properties no longer accepts three-part values such as top right 20%. This change also applies to basic shapes and gradients. Valid position values must always have 1, 2, or 4 parts.

Blink > HTML

Following a specification change, ImageCapture.prototype.setOptions() has been removed.

Blink > Input

Following a specification change, document.createTouch() and document.createTouchList() have been removed.

Blink > Web Audio

Following a specification change, automatic dezippering of AudioParam.prototype.value changes was removed from Chrome. If you need to smooth the value of AudioParam changes, use AudioParam.prototype.setTargetAtTime().

Under the hood: How Chrome's ad filtering works

While most advertising on the web is respectful of user experience, over the years we've increasingly heard from our users that some advertising can be particularly intrusive. As we announced last June, Chrome will tackle this issue by removing ads from sites that do not follow the Better Ads Standards. We've previously discussed some of the details surrounding how Chrome protects users from intrusive ads, but as we approach the launch date of February 15, we wanted to go under the hood and discuss how this feature works in more detail.

What are the Better Ads Standards?
The Better Ads Standards are the result of public consumer research by the Coalition for Better Ads, an industry group focused on improving users' experience with online advertising. Over 40,000 internet users in North America and Europe participated in surveys where they were shown common ad experiences and asked to evaluate how intrusive the experiences were. The most intrusive ad experiences include prestitial ads (those full-page ads that block you from seeing the content on the page) and flashing animated ads. More details about the research and methodology can be found on the Coalition's website.

Although a few of the ad experiences that violate the Better Ads Standards are problems in the advertisement itself, the majority of problematic ad experiences are controlled by the site owner — such as high ad density or prestitial ads with countdown. This result led to the approach Chrome takes to protect users from many of the intrusive ad experiences identified by the Better Ads Standards: evaluate how well sites comply with the Better Ads Standards, inform sites of any issues encountered, provide the opportunity for sites to address identified issues, and remove ads from sites that continue to maintain a problematic ads experience.

Today, the Better Ads Standards consists of 12 ad experiences that research found to be particularly annoying to users. Image Source: Coalition for Better Ads

Evaluating sites for violations
Sites are evaluated by examining a sample of pages from the site. Depending on how many violations of the Better Ads Standards are found, the site will be evaluated as having a status of Passing, Warning, or Failing. The evaluation status of sites can be accessed via the Ad Experience Report API. Site owners can also see more detailed results, such as the specific violations of the Better Ads Standards that were found, via the Ad Experience Report in Google’s Search Console. From the Report site owners can also request that their site be re-reviewed after they have addressed the non-compliant ad experiences.

The Ad Experience Report in Google's Search Console allows site owners to see their overall site evaluation status, as well as the specifics of any violations identified on their site.

Filtering on sites at the network level
At a technical level, when a Chrome user navigates to a page, Chrome’s ad filter first checks if that page belongs to a site that fails the Better Ads Standards. If so, network requests on the page — such as those for JavaScript or images — are checked against a list of known ad-related URL patterns. If there is a match, Chrome will block the request, preventing the ad from displaying on the page. This set of patterns is based on the public EasyList filter rules, and includes patterns matching many ad providers including Google’s own ad platforms, AdSense and DoubleClick.

What this looks like in Chrome
Chrome will automatically block ads on sites that fail the Better Ads Standards, using the approach described above. When at least one network request has been blocked, Chrome will show the user a message indicating that ad blocking has occurred as well as an option to disable this setting by selecting “allow ads on this site.” For desktop users, the notification in Chrome's address bar will look similar to Chrome's existing pop-up blocker. Android users will see message in a small infobar at the bottom of their screen, and can tap on “details” to see more information and override the default setting.

Chrome will automatically block intrusive ads on sites that have been found to violate the Better Ads Standards, but users have the option to disable the feature by selecting “allow ads on this site.” 

Early results show positive progress for users
While the result of this action is that Chrome users will not see ads on sites that consistently violate the Better Ads Standards, our goal is not to filter any ads at all but to improve the experience for all web users. As of February 12, 42% of sites which were failing the Better Ads Standards have resolved their issues and are now passing. This is the outcome we were hoping for — that sites would take steps to fix intrusive ads experiences themselves and benefit all web users. However, if a site continues to maintain non-compliant ad experiences 30 days after being notified of violations, Chrome will begin to block ads on that site.

We're encouraged by early results showing industry shifts away from intrusive ad experiences, and look forwarding to continued collaboration with the industry toward a future where Chrome's ad filtering technology will not be needed.

Posted by Chris Bentzel, Engineering Manager

Chrome 65 Beta: CSS Paint API and the ServerTiming API

Unless otherwise noted, changes described below apply to the newest Chrome Beta channel release for Android, Chrome OS, Linux, Mac, and Windows.

The CSS Paint API, also known as “CSS Custom Paint”, allows developers to programmatically generate an image whenever a CSS property expects one. Instead of referencing an image resource, developers can now use the new paint() function to reference a paint worklet that will draw the image. This API can be used for many things, including making the DOM tree smaller and transferring significantly less data compared to an image.

background-image: paint(checkerboard);

To see the paint worklet in action, check out our explainer and the video demo below.

In this example, the CSS Paint API is used to programmatically create a checkerboard image.
Server Timing API
Developers interested in measuring the performance of their web applications have been able to use the Navigation Timing and Resource Timing APIs to request timing data for the document and its resources. Until now, there has been no way for the server to send any details about its response time to the client. The new Server Timing API allows web servers to pass performance timing information via HTTP headers to browsers. This new API provides developers a more complete performance picture that includes the speed of both the client and the server. For example, Chrome Developer Tools now shows server timing performance information via the Server Timing API.

Screenshot of the Chrome Developer Tools integration of the ServerTiming API.

Other features in this release

Blink > CSS

Blink > DOM

Blink > Feature Policy

Blink > Network

  • To match compatibility with the TLS spec, Chrome now supports the draft-23 version of the TLS 1.3 protocol.
  • Developers can use Request.destination to evaluate which resource their service worker is fetching.

Blink > Performance APIs

  • As WebIDL was deprecated, PerformanceResourceTiming, PerformanceLongTaskTiming, and TaskAttributionTiming now support the toJSON method to convert objects to JSON.

Blink > Security

  • To protect users against cross-origin information leakage, Chrome will ignore the presence of the download attribute on anchor elements with cross-origin attributes.

Deprecations and interoperability improvements

Blink > Bindings

  • To match compatibility with the HTML spec, document.all is no longer overwritable.

Blink > Network

  • As previously announced, Chrome 65 will not trust certificates issued from Symantec’s Legacy PKI after December 1st, 2017, and will result in interstitials. This will only affect site operators who explicitly opted-out of the transition from Symantec’s Legacy PKI to DigiCert’s new PKI, and does not apply to the previously disclosed independent sub-CAs from this infrastructure.
For a complete list of all features (including experimental features) in this release, see the Chrome 65 milestone hotlist.

Posted by Ian Kilpatrick, Patiently Painting Engineer

A secure web is here to stay

For the past several years, we’ve moved toward a more secure web by strongly advocating that sites adopt HTTPS encryption. And within the last year, we’ve also helped users understand that HTTP sites are not secure by gradually marking a larger subset of HTTP pages as “not secure”. Beginning in July 2018 with the release of Chrome 68, Chrome will mark all HTTP sites as “not secure”.

In Chrome 68, the omnibox will display “Not secure” for all HTTP pages.

Developers have been transitioning their sites to HTTPS and making the web safer for everyone. Progress last year was incredible, and it’s continued since then:

Chrome is dedicated to making it as easy as possible to set up HTTPS. Mixed content audits are now available to help developers migrate their sites to HTTPS in the latest Node CLI version of Lighthouse, an automated tool for improving web pages. The new audit in Lighthouse helps developers find which resources a site loads using HTTP, and which of those are ready to be upgraded to HTTPS simply by changing the subresource reference to the HTTPS version.

Lighthouse is an automated developer tool for improving web pages.

Chrome’s new interface will help users understand that all HTTP sites are not secure, and continue to move the web towards a secure HTTPS web by default. HTTPS is easier and cheaper than ever before, and it unlocks both performance improvements and powerful new features that are too sensitive for HTTP. Developers, check out our set-up guides to get started.

Posted by Emily Schechter, Chrome Security Product Manager

Further protecting users from deceptive or confusing inline installation

Since 2012, Chrome has enabled extension developers to provide a smooth installation experience on their own pages using inline installation. We have also worked hard to prevent abuse of this feature by disabling inline installation in cases where we detect misleading or deceptive installation flows. User complaints have been reduced by 65% since the start of this disabling initiative. Fewer than 3% of extensions still engage in these deceptive or confusing install flows, but this subset of extensions generates 90% more user complaints on average than the rest of the extensions in the Chrome Web Store.

As part of our ongoing efforts to protect users, we are expanding our abuse protections to further reduce user harm. Starting in a few weeks, we will upgrade our automated inline installation abuse detection to improve our detection speed and better detect extensions using deceptive or confusing installation flows.

In addition to the existing extension-level protection, our expanded enforcement will also use machine learning to evaluate each inline installation request for signals of deceptive, confusing, or malicious ads or webpages. When we find those signals, we’ll selectively disable that one inline installation request and redirect the user to the extension’s page on the Chrome Web Store. This selective enforcement will not impact inline installation of that extension from other, non-deceptive sources.

We’ve taken these measures to preserve a good experience for Chrome users and developers in the Chrome Web Store. More information is available in the Inline Installation Enforcement FAQ.

Posted by Nav Jagpal and Benjamin Ackerman, Safe Browsing Team

Chrome 64 Beta: stronger pop-up blocker, Resize Observer, and import.meta

Unless otherwise noted, changes described below apply to the newest Chrome Beta channel release for Android,
Chrome OS, Linux, Mac, and Windows.

Stronger pop-up blocker
1 out of every 5 user feedback reports submitted on Chrome for desktop mention some type of
unwanted content. Examples include links to third-party websites disguised as play buttons or other
site controls, or transparent overlays on websites that capture all clicks and open new tabs or
windows. In this release, Chrome's pop-up blocker now prevents sites with these types of abusive
experiences from opening new tabs or windows. Site owners can use the Abusive Experiences
Report in Google Search Console to see if any of these abusive experiences have been found on
their site and improve their user experience.

Two types of abusive experiences where a deceptive site control appears to do one thing, but has a different behavior when clicked. One looks like a play button on a video but sends the user to an unwanted download when clicked (left), and the other looks like a close button but instead opens unwanted pop-up windows (right).

Resize Observer
Traditionally, responsive web applications have used CSS media queries or window.onresize to
build responsive components that adapt content to different viewport sizes. However, both of these
are global signals and require the overall viewport to change in order for the site to respond
accordingly. Chrome now supports the Resize Observer API to give web applications finer
control to observe changes to sizes of elements on a page.

const ro = new ResizeObserver((entries) => {
 for (const entry of entries) {
   const cr = entry.contentRect;
   console.log(`Element size: ${cr.width}px × ${cr.height}px`);
   console.log(`Element padding: ${}px / ${cr.left}px`);

// Observe one or multiple elements
The code snippet above uses the Resize Observer API to observe changes to an element.

Developers writing JavaScript modules often want access to host-specific metadata about the
current module. To make this easier, Chrome now supports the import.meta property within
modules that exposes the module URL via import.meta.url. Library authors might want to
access the URL of the module being bundled into the library to more easily resolve resources
relative to the module file as opposed to the current HTML document. In the future, Chrome plans to
add more properties to import.meta.

Other features in this release

Blink > Animation

  • The offset-path property can be used to animate an element by specifying the geometry of the path that an element moves along.




  • To improve developer experience, Chrome now supports named captures in regular expressions, allowing developers to assign meaningful names to portions of a string that a regular expression matches.
  • Chrome now supports the Unicode property escapes \p{…} and \P{…} for regular expressions that have the u flag set, allowing developers to create more powerful Unicode-aware regular expressions.
  • To assist with local-aware formatting of strings produced by internationalization formatters, developers can now use Intl.NumberFormat.prototype.formatToParts() to format a number to a list of tokens and their type. Thanks to Igalia for helping make this happen!



  • Developers can now use the cache option to specify the cache mode of a Request.
  • Developers can now use Request.prototype.cache to view the cache mode of a Request and determine whether a request is a reload request.  

Blink>Permissions API

  • To better align with the Permissions API spec, the Permissions API can now be used to query the status of the camera and microphone permissions.


  • In Focus Management APIs, developers can now focus an element without scrolling to it by using the preventScroll attribute.



  • AudioWorklet, an API that exposes low-level audio processing capability to support custom AudioNodes, is now available in origin trials and the experimental flag.


  • To align with the WebRTC 1.0 spec, RTCPeerConnection now supports addTrack() for single stream use cases, as well as removeTrack(), getSenders(), ontrack, and a minimal version of the RTCRtpSender interface.


  • To improve interoperability and end user experience, window.alert() no longer brings a backgrounded tab to the foreground but instead shows the alert when the user switches to the background tab.


Deprecations and interoperability improvements

Blink> CSS

Blink> DOM

Blink> Performance APIs

For a complete list of all features (including experimental features) in this release, see the
Chrome 64 milestone hotlist.  
Posted by Charles Harrison, Pop-Up Popping Engineer

Reducing Chrome crashes caused by third-party software

Roughly two-thirds of Windows Chrome users have other applications on their machines that interact with Chrome, such as accessibility or antivirus software. In the past, this software needed to inject code in Chrome in order to function properly; unfortunately, users with software that injects code into Windows Chrome are 15% more likely to experience crashes. With Chrome extensions and Native Messaging, there are now modern alternatives to running code inside of Chrome processes. Starting in September 2018, Chrome 69 will begin blocking third-party software from injecting code into Chrome on Windows.

These changes will take place in three phases. In April 2018, Chrome 66 will begin showing affected users a warning after a crash, alerting them that other software is injecting code into Chrome and guiding them to update or remove that software.

In Chrome 66 a warning will be shown to users with third-party software that injects into Chrome.

In September 2018, Chrome 69 will begin blocking third-party software from injecting into Chrome processes. If this blocking prevents Chrome from starting, Chrome will restart and allow the injection, but also show a warning that guides the user to remove the software. Finally, in January 2019, Chrome 72 will remove this accommodation and always block code injection.

While most software that injects code into Chrome will be affected by these changes, there are some exceptions. Microsoft-signed code, accessibility software, and IME software will not be affected. As with all Chrome changes, developers are encouraged to use Chrome Beta for early testing.

Fewer crashes means more happy users, and we look forward to continuing to make Chrome better for everyone.

Posted by Chris Hamilton, Chrome Stability Team

Updated 2018-06-21: Third-party software will be blocked from injecting code into Chrome on Windows starting in Chrome 69.

Expanding user protections on the web

One of the advantages of the web is that it allows developers to create any type of experience they can imagine, which has led to the rich diversity of content available on the web today. While most content producers are interested in providing excellent experiences for their users, we've found that a small number use the flexibility and power of the web to take advantage of users and redirect them to unintended destinations. 1 out of every 5 feedback reports from Chrome users on desktop mention encountering some type of unwanted content, and we take this feedback seriously when considering how to improve Chrome. Following on from features like Chrome's pop-up blocker and autoplay protections, over the next few releases we'll be rolling out three new protections designed to give users all the web has to offer, but without many of these types of unwanted behaviors.

One piece of feedback we regularly hear from users is that a page will unexpectedly navigate to a new page, for seemingly no reason. We've found that this redirect often comes from third-party content embedded in the page, and the page author didn't intend the redirect to happen at all. To address this, in Chrome 68 all redirects originating from third-party iframes will show an infobar instead of redirecting, unless the user had been interacting with that frame. This will keep the user on the page they were reading, and prevent those surprising redirects.
An example of a redirect being blocked on a test site. The iframes embedded in the site are attempting to navigate the page to an unintended destination, but Chrome prevents the redirect and shows an infobar.

When the user interacts with content, things can also go wrong. One example that causes user frustration is when clicking a link opens the desired destination in a new tab, while the main window navigates to a different, unwanted page. Starting in Chrome 68 we'll also detect this behavior, trigger an infobar, and prevent the main tab from being redirected. This allows the user to continue directly to their intended destination, while also preserving the context of the page they came from.

Finally, there are several other types of abusive experiences that send users to unintended destinations but are hard to automatically detect. These include links to third-party websites disguised as play buttons or other site controls, or transparent overlays on websites that capture all clicks and open new tabs or windows. 
Two types of abusive experiences where a deceptive site control appears to do one thing, but has a different behavior when clicked. One looks like a play button on a video but sends the user to an unwanted download when clicked (left), and the other looks like a close button but instead opens unwanted pop-up windows (right).

Similar to how Google Safe Browsing protects users from malicious content, starting in early January Chrome's pop-up blocker will prevent sites with these types of abusive experiences from opening new windows or tabs. To help site owners prepare for this change, today we're also launching the Abusive Experiences Report alongside other similar reports in the Google Search Console. Site owners can use the report to see if any of these abusive experiences have been found on their site and improve their user experience. Otherwise, abusive experiences left unaddressed for 30 days will trigger the prevention of new windows and tabs.

Together, these protections will dramatically improve users' web browsing experiences while still allowing them access to all that the web has to offer. 

Posted by Ryan Schoen, Product Manager

Update 2018-06-07: The two protections described above that prevent unwanted redirects and unwanted tabs or windows are now scheduled to be released with Chrome 68. The timeline for expanding Chrome's pop-up blocker remains unchanged, as it already launched in January.

Chrome 63 Beta: Dynamic module imports, async iterators and generators, Device Memory API, and permissions UI changes

Unless otherwise noted, changes described below apply to the newest Chrome Beta channel release for Android, Chrome OS, Linux, Mac, and Windows.

Dynamic module imports

Currently, importing JavaScript modules is completely static, and developers cannot import modules based on runtime conditions, like whether a user is logged in. Starting in this release, the import(specifier) syntax now allows developers to dynamically load code into modules and scripts at runtime. This  can be used for lazy loading a script only when it’s needed, which improves performance of the application.

button.addEventListener('click', event => {
   .then(dialogBox => {;
   .catch(error => {
       /* Error handling */
The code example above shows how to use the import(specifier) function to import JavaScript after an event.

Async iterators and generators

Writing code that does any sort of iteration with async functions can be inelegant. The new async generator functions using the async iteration protocol are now available to help developers streamline the consumption or implementation of streaming data sources. Async iterators can be used in for loops and also to create custom async iterators through async iterator factories.
async function* getChunkSizes(url) {
 const response = await fetch(url);

 for await (const chunk of streamAsyncIterator(response.body)) {
   yield chunk.length;
The code example above shows how to use async iterators to writer cleaner code for streaming fetches, using the streamAsyncIterator function.

Device Memory API

It’s challenging for developers to create one user experience that can work across all devices, due to varying device capabilities. The new Device Memory JavaScript API helps developers with this challenge by using the total RAM on a user’s machine to provide insights into device constraints. This insight enables developers to tailor content at runtime in accordance with hardware limitations. For example, developers can serve a “lite” app to users on low-end devices, resulting in better experiences and fewer frustrations. The Device Memory API can also be used to add context to metrics, such as the amount of time a task takes to complete in JavaScript, through the lens of device memory.

Permissions UI changes

When websites need special permissions from a user, they trigger a permission request. Currently these permission requests appear in Chrome for Android as ignorable banners at the bottom of the screen, and developers often show them without considering whether the user has the appropriate context to grant the permission. This results in a distracting user experience, and users ignore or temporarily dismiss these permission prompts more than 90% of the time.

In Chrome 59, we started to address this problem by temporarily blocking a permission if the user dismisses the request three times. As a next step, in this release Chrome for Android now presents permission requests as modal dialogs. This change reduces the overall number of permission prompts by 50%. It also makes users 5 times more likely to accept or deny requests, rather than temporarily dismissing or repeatedly ignoring them. To ensure users understand the permission request, developers should present users with permission requests at an appropriate time, as we’ve found that users were 2.5 times more likely to grant permission to a site that ask for permissions with context.

Other features in this release

Blink > Bindings

Blink > CSS

Blink > Fonts

Blink > HTML

Blink > JavaScript

Blink > MediaStream

Blink > Network

Blink > Sensor

Blink > Storage

UI > Browser > Mobile (Android)

Deprecations and interoperability improvements

Blink > Bindings

Blink > CSS

Blink > DOM

Sathya Gunasekaran, Lazily-Loaded Engineer