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Unless otherwise noted, changes described below apply to the newest Chrome Beta channel release for Android, Chrome OS, Linux, macOS, and Windows. Find more information about the features listed here through the provided links or from the list on ChromeStatus.com. Chrome 76 is beta as of June 13, 2019.

Dark mode

Many operating systems now support inverted color schemes with a system setting referred to as ‘dark theme' or ‘dark mode', depending on the system.


The prefers-color-scheme media query allows a website or web app to adopt the preferred display mode of the user. Use the query in your CSS code like so:


@media (prefers-color-scheme: dark) {
  body {
    color: white;
    background-color: black;
  }
}


What is left out of this is the explanation? For that, read the article titled Hello Darkness, My Old Friend.

Payments API

Over the last few versions of Chrome we've rolled out a number of improvements to the payments APIs. These APIs provide a way to interact with proprietary payment systems without needing to build your own user interactions. Changes in Chrome 75 included replacing hasEnrolledInstrument() with canMakePayment() and removal of languageCode from the billing address. With the detailsPromise option Chrome 75 gives PaymentRequest.show() a means of performing a quick server call before showing payment details to the buyer.

Chrome 76 brings three changes to the payment realm. Now implemented are features that allow a merchant website or web app to respond when a user changes payment instruments. Additionally, the PaymentRequestEvent has a new method called changePaymentMethod() and the PaymentRequest object now supports an event handler called paymentmethodchange. You can use both to notify a merchant when the user changes payment instruments. The former returns a promise that resolves with a new PaymentRequest instance.

Additionally, Chrome now makes it easier to use the payments APIs for self-signed certificates on the local development environment. To do this, launch Chrome from a command line with the —ignore-certificate-errors flag.

For detailed information about these features, read Web Payments Updates.

Improvements for Progressive Web Apps

Install Progressive Web Apps on the desktop with ease

On desktop, there is typically no indication to a user that a Progressive Web App is installable, and if it is, the install flow is hidden within the three dot menu.

In Chrome 76, we're making it easier for users to install Progressive Web Apps on the desktop by adding an install button to the omnibox.


If a site meets the Progressive Web App installability criteria, Chrome shows an install icon in the omnibox. There is no extra work required from developers. Clicking the button prompts the user to install the PWA.

Control the Add to Home Screen mini-infobar

In Chrome 76, we're giving you control over the add to home screen mini-infobar.




Chrome shows the mini-infobar the first time a user visits a site that meets the Progressive Web App installability criteria. Developers want to prevent the mini-infobar from appearing, and provide their own install promotion instead.

To do this, listen for the beforeinstallprompt event, and call preventDefault()
on it. Then, update your UI to notify the user by adding an install button or other element. Depending on your app, there are several different patterns you can use to promote installation of your PWA.

The add to home screen mini-infobar is still a temporary measure. We are experimenting with new UI patterns for giving Progressive Web App users the ability to install, and do this in a way that reduces clutter in the browsing experience.

Updating WebAPKs more frequently

When a PWA is installed on Android, Chrome automatically requests and installs a WebAPK. Chrome periodically checks to see if the manifest has changed, and if a new WebAPK is required. Starting in Chrome 76, Chrome will check the manifest more frequently: checking every day, instead of every three days. If any of the key properties have changed, Chrome will request and install a new WebAPK.

Other features in this release

Animation.updatePlaybackRate

Adds Animation.updatePlaybackRate(), which lets you seamlessly transition the playback rate of an animation such that there is no visible jump in the animation. Current time is preserved at the instance the new playback rate takes effect.

Async clipboard: read and write images

Implements programmatic copying and pasting of images for the Async Clipboard API. This change also updates navigator.clipboard.read() and navigator.clipboard.write() to comply with the specification. Programmatic copying and pasting of images is Chromium's top starred bug.

Escape key is not a user activation

The escape key is no longer treated as a user activation. Browsers prevent calls to abusable APIs (like popup, fullscreen, vibrate, etc.) unless the user activates the page through direct interactions. Not all interactions trigger user activation. For example, clicking on a link or typing in a textbox does, but swiping fingers on a screen or hovering with the mouse cursor does not. Since users never intend to interact with the page through the escape key, it should not trigger user activation.

Fetch Metadata

Introduces a new HTTP request header that sends additional metadata about a request's provenance (is it cross-site, is it triggered from <img>, etc.) to the server to allow it to make security decisions which might mitigate some kinds of attacks based on timing the server's response (XSS leaks and others).

For example, it is unlikely that a bank's "Transfer all money" endpoint would be referenced from an <img> tag, and likewise unlikely that evil.com is going to be making any legitimate requests whatsoever. Ideally, the server could reject these requests a priori rather than deliver them to the application backend.

form.requestSubmit()

Adds the form.requestSubmit() function, which requests form submission. It includes interactive constraint validation, dispatches a submit event, and takes a reference to the submitter button.

ImageCapture support for focusDistance constraint

The Image Capture API provides a means to set the focusMode to manual which is not useful if you cannot set the focus distance. This change provides an interface for getting focus range values and setting focus distance value.

Implement Animation.pending

Adds the pending attribute to the Web Animations API. A pending animation is one that is waiting on an asynchronous operation that affects the play state. Adding support for this attribute does not affect the rendering or timing of animations, but simply exposes the signal.

IndexedDB transaction explicit commit API call

Adds a commit() function to IDBTransaction objects, which explicitly marks a transaction as not accepting further requests. Currently, IndexedDB only commits a transaction after all associated requests have had their completion event handlers executed, and no new requests have been queued by the event handlers. Developers can use the explicit commit() function to shave a few event loop cycles off of the latency of their transactions.

The primary benefit of explicit commit is that it increases the throughput of read and write requests made on an object store. This is a clear performance benefit in terms of the rate at which operations can be processed. Additionally, the increase in speed is advantageous because it adds stability to IndexedDB by reducing the probability that a disruptive event occurs within the lifetime of a transaction.

JavaScript

DateTimeFormat dateStyle and timeStyle
Adds dateStyle and timeStyle options to functions on Intl.DateTimeFormat, specifically formatToParts() and resolveOptions(). These options provide a compact way to request the appropriate, locale-specific date and time of given length styles.

Locale sensitive BigInt.prototype.toLocaleString and allow Intl.NumberFormat format/formatToParts to take BigInt.
Changes BigInt.prototype.toLocaleString() to locale-sensitive number formatting and changes Intl.NumberFormat.prototype.format() and formatToParts() to accept BigInt as input.

Media capabilities in workers

Enables the Media Capabilities API in all types of workers to help website and web apps pick the best media to stream from a worker. The information can then be used to create the MediaStream from a worker.

Promise.allSettled

Adds Promise.allSettled(), which returns a promise that is fulfilled with an array of promise state snapshots, but only after all the original promises have settled, in other words after it has either resolved or rejected.

Simpler reading methods for Blob interface

Adds three new methods to the Blob interface to perform read operations: text(), arrayBuffer(), and stream().

WebRTC

RTCSctpTransport
Exposes information about the SCTP transport that is used to carry WebRTC data channels such as max-message-size and max channels.

RTCRtpSender.setStreams
Allows changing the association between the track associated with an RTCRtpSender and streams. Stream association causes tracks in the same stream to be synchronized. This is useful, for example, if during a call a user switches from a front-facing camera to a back-facing camera and the application uses RTCRtpSender.replaceTrack(). On the receiving end the new track must be associated with the existing stream and synchronized with its auto track.

RTCRtpTransceiver.setCodecPreferences()
Adds the setCodecPreferences() method, which overrides the default codec preferences used by the user agent. This allows applications to disable the negotiation of specific codecs. It also allows an application to cause a remote peer to prefer the codec that appears first in the list for sending.

white-space: break-spaces

The white-space:break-spaces value allows authors to specify that any sequence of preserved white space that would otherwise overflow a line and hang (as per the CSS Text Module specification's Trimming and Positioning rules) must be broken.

Removals

Remove feature policy: lazyload

The lazyload feature policy was intended to allow developers to selectively control the lazyload attribute on the <iframe> and <img> tags to provide more control over loading delay for embedded contents and images on a per origin basis.

The policy is removed in favor of a newer feature policy for loading, namely loading-frame-default-eager which is more aligned with how the loading attribute will be used. The removal applies to both the Feature-Policy header and the <iframe> allow attribute.

Remove outputs from MediaStreamAudioDestinationNode

According to the specification, the MediaStreamAudioDestinationNode in the Web Audio API should have no outputs. Chrome's implementation has a single output which has been removed.

Remove insecure usage of DeviceMotionEvent

Chromium has been showing deprecation warnings since 2015 whenever the API is used in a non-secure browsing context. Chrome now restricts the API to secure browsing contexts. This change brings Chromium's implementation in line with the privacy and security recommendations in the specification, and is aligned with the effort to deprecate powerful features on insecure origins.

Remove insecure usage of DeviceOrientationEvent

Chromium has been showing deprecation warnings since 2015 whenever the API is used in a non-secure browsing context. Chrome now restricts the API to secure browsing contexts. This change brings Chromium’s implementation in line with the privacy and security recommendations in the specification, and is aligned with the effort to deprecate powerful features on insecure origins.

Debugging web pages displayed in Chrome for iOS has always required building the project from source because the release version of WKWebView does not support Safari Remote Debugging. To help bridge the gap of missing developer support, we added the chrome://inspect page in M73 to locally view JavaScript logs. While building Chrome for iOS from source is still the best way to fully debug web pages, we hope that this tool will make it easier to troubleshoot some problems.
Background
When building Chrome for iOS from source, Safari Web Inspector can be used to debug a web page rendered in Chrome. However, this takes a non-trivial amount of effort which includes setting up a Chromium checkout, installing a current version of Xcode, and waiting for the build to complete. Additionally, a Mac with enough disk space to hold the code and tools is required. This barrier to debugging has led to bugs being filed for specific website failures on Chrome for iOS.


These bugs can be difficult to diagnose as they are generally based on a single failure case. Chrome developers most likely don’t know the website application well enough to fully understand what is causing the bug. Often, the reporter has even spent time to build a dedicated test page to more precisely understand the issue. The lack of debugging tools require developers to come up with alternative methods in order to debug their websites. Of course, nothing is wrong with filing bugs, and we certainly don’t want to discourage it, but we do want to improve the web developer experience.
In-app JavaScript Console
Enable JavaScript log collection by navigating to chrome://inspect in Chrome for iOS and leaving that tab open to collect logs. In another tab, reproduce the case for which you are interested. Then switch back to the chrome://inspect tab to view the collected logs.  (Log collection will stop if the chrome://inspect page closes or navigates and logs will be lost as they are not persisted.)

Posted by Mike Dougherty, Chrome Engineer on iOS

The ECMA committee is working hard on designing the next version of JavaScript, also known as "Harmony". It is due by the end of next year and it is going to be the most comprehensive upgrade in the history of this language.

Chrome and V8 are committed to pushing JavaScript forward and have already started implementing the new features. You can try some of them today in the latest dev channel release. Here’s a summary:

  • Lexical scoping. Now "let" is the new "var" – traditional "var" declarations are complemented with "let" and "const". Both are properly block-scoped bindings, eliminating a common source of errors and weird behaviour. Function declarations are now officially allowed in local scope as well, and also obey lexical scoping. (Note: Lexical scoping is only available in ES strict mode.)
  • Collections. Efficient maps and sets will make your life easier. Any value can be used as a key or element, including objects. No surprises, no more need to abuse objects as dictionaries. (Caveat: Iteration over collections is not yet specified.)
  • Weak maps. A special kind of map for which the garbage collector determines when a key is no longer reachable, so that the key-value pair can be removed from the map automatically. This goes a long way towards avoiding memory leaks in long-lived tables and relieves the developer from worrying about stale entries.
  • Proxies. A proxy simulates a JavaScript object or function, and can customize just about any aspect of their behaviour that you can imagine. This is a real power feature, that takes reflection to a new level and can be used to implement various advanced abstractions and interfaces
 ...and there is a lot more to come, as the V8 team will continue working on bringing new Harmony features to you.

To enable Harmony features in the latest dev channel release of Chrome, go to chrome://flags and toggle on "Experimental JavaScript features". We encourage you to try them out and give us feedback!

The V8 benchmark suite contains a number of pure JavaScript benchmarks that capture the areas in which a JavaScript engine has to perform well to support the well-structured, maintainable, and high-performance web applications of tomorrow. These benchmarks have been useful for us when optimizing the V8 JavaScript engine and we have found that making them run faster leads to better performance for many of the web applications we enjoy using every day.

Today we have released version 6 of the V8 benchmark suite. The main changes are in the RegExp and Splay components of the benchmark suite. For reference, we describe each of the existing benchmarks in the suite below, along with any changes made in version 6.

RegExp: Regular expression benchmark generated by extracting regular expression operations from 50 of the most popular web pages. The regular expressions are exercised a number of times to reflect their popularity on those top 50 web pages. Changed in version 6: each regular expression is now exercised on a number of different input strings instead of just one.
Splay: Data manipulation benchmark that modifies a large splay tree to exercise the automatic memory management subsystem. The benchmark builds a large splay tree in a setup phase and then measures how fast nodes can be added and removed. Changed in version 6: no longer converts the same numeric key to string repeatedly and updates the splay tree in a way that increases the pressure on the memory management subsystem.

Richards: Operating system kernel simulation benchmark originally written in BCPL by Martin Richards. The Richards benchmark effectively measures how fast the JavaScript engine is at accessing object properties, calling functions, and dealing with polymorphism. It is a standard benchmark that has been successfully used to measure the performance of many modern programming language implementations.

DeltaBlue: One-way constraint solver, originally written in Smalltalk by John Maloney and Mario Wolczko. The DeltaBlue benchmark is written in an object-oriented style with a multi-level class hierarchy. As such it measures how fast the JavaScript engine is at running well-structured applications with many objects and small functions. Changed in version 6: fixed a couple of typos that do not have any impact on the behavior of the benchmark.

Crypto: Encryption and decryption benchmark based on code by Tom Wu. The benchmark encrypts an input string, decrypts the result and verifies that encryption followed by decryption yields the original input. The encryption/decryption algorithm is RSA and the benchmark measures the performance of arithmetic operations on integers and array access.

RayTrace: Ray tracer benchmark based on code by Adam Burmister. The benchmark measures floating-point computations where the object structure is constructed using the Prototype JavaScript library. Changed in version 6: removed dead code that has no impact on the behavior of the benchmark.

EarleyBoyer: Classic Scheme benchmarks, translated to JavaScript by Florian Loitsch's Scheme2Js compiler. The benchmarks exercise important areas of the JavaScript engine such as object allocation, data structure manipulation, and garbage collection. The translated nature of the benchmarks make them appear foreign, but the runtime characteristics of the benchmarks are highly representative of many real world web applications.

Curious to know how your browser performs? Give it a spin on the new version of the V8 benchmark suite.

Last June, we launched the Sputnik JavaScript conformance test suite, a comprehensive set of more than 5000 tests. Today we're releasing a test runner for Sputnik, that allows you to easily run the complete test suite from within your browser.

Sputnik touches all aspects of the JavaScript language defined in the 3rd edition of the ECMA-262 spec. In many ways it can be seen as a continuation of and a complement to existing browser conformance testing tools, such as the Acid3 test. While we are always focused on improving speed, Sputnik is not about testing how fast your browser executes JavaScript, but rather whether it does so correctly.

Since we released the Sputnik tests as an open source project, the most requested feature has been the ability to run the tests in a browser, and we are excited to launch that functionality today. The new test runner lets you run the tests from a single URL and quickly see the results in your browser. This makes it easier both for users to see how well their browser conforms to the JavaScript spec, as well as for browser makers to find bugs and incompatibilities.

You can also use Sputnik to compare browser conformance. For example, below is an experimental plot that compares five popular browsers and which we hope to update as new stable versions of the browsers are released. We created this chart by running Sputnik in each of the five browsers and then plotting each browser such that the fewer tests a browser fails the closer it is to the center and the more failing tests two browsers have in common the closer they are placed to each other. In this example, when running Sputnik on a Windows machine, we saw the following results: Opera 10.50: 78 failures, Safari 4: 159 failures, Chrome 4: 218 failures, Firefox 3.6: 259 failures and Internet Explorer 8: 463 failures.


When we first released the Sputnik test suite we noted that to be compatible with the web you sometimes had to be incompatible with the JavaScript spec. Since then a new version of the spec, ECMAScript 5, has been released. Besides introducing a number of new language features, ECMAScript 5 changes how many existing features are defined to bring them in line with how they are used on the web. We are updating the Sputnik tests to reflect those changes so that 0 failures would mean not only compatibility with the spec but also compatibility with the web.

We are excited to see the efforts on conformance testing by other browser makers. For example, where Sputnik tests the language features in ECMAScript 5 which were also present in ECMAScript 3, Microsoft's es5conform project tests the new language features that were added in ECMAScript 5.

Incompatibilities between browsers remain one of the biggest challenges for web developers. We hope that giving users and browser vendors an easy way to test their browser will help promote browser robustness and compatibility across the industry.