Autoplay

Update (November 22, 2018)

For the Web Audio API, the Autoplay Policy will launch in M71.

Update (May 15, 2018)

The Autoplay Policy launched in M66 Stable for <video> and <audio> and is effectively blocking roughly half of unwanted media autoplays in Chrome.

For the Web Audio API, the autoplay policy will launch in M70. This affects web games, some WebRTC applications, and other web pages using audio features. Developers will need to update their code to take advantage of the policy. More detail can be found in the Web Audio API section below.

Summary This policy controls when video and audio is allowed to autoplay, and is designed to meet three primary goals:

• Provide user control over what content can autoplay
• Enable legitimate uses of autoplay without complicated workarounds
• Make progress towards consistent policies across mobile and desktop platforms

Under the new policy media content will be allowed to autoplay under the following conditions:

• The content is muted, or does not include any audio (video only)
• The user tapped or clicked somewhere on the site during the browsing session
• On mobile, if the site has been added to the Home Screen by the user
• On desktop, if the user has frequently played media on the site, according to the Media Engagement Index

By default embedded IFrames will only be able to play muted or silent videos. However, if site owners wish for IFrames on their site to be able to play unmuted content, they may pass the autoplay permissions to the IFrame using allow=autoplay. This attribute allows any video contained in the IFrame to play as if it were hosted on the site. For a more detailed design and rationale, please click here. Autoplay blocking Around the same time we will be making two additional changes related to autoplay that will make muted autoplay more reliable. These two changes will make it possible for sites and advertisers to use muted videos instead of animated .gifs, which in most cases will reduce overall bandwidth consumption.

• Removing the block autoplay setting that is currently available on Chrome for Android
• Removing autoplay blocking on mobile when data saver mode is enabled

Developer Recommendations: <video> and <audio>

• Use autoplay sparingly. Autoplay can be a powerful engagement tool, but it can also annoy users if undesired sound is played or they perceive unnecessary resource usage (e.g. data, battery) as the result of unwanted video playback.
• If you do want to use autoplay, consider starting with muted content and let the user unmute if they are interested in exploring more. This technique is being effectively used by numerous sites and social networks.
• Unless there is a specific reason to do so, we recommend using the browser’s native controls for video and audio playback. This will ensure that autoplay policies are properly handled.
• If you are using custom media controls, ensure that your website functions properly when autoplay is not allowed. We recommend that you always look at the promise returned by the play function to see if it was rejected:

var promise = document.querySelector('video').play();

if (promise !== undefined) {

promise.then(_ => {

// Autoplay started!

}).catch(error => {

// Autoplay was prevented.

// Show a "Play" button so that user can start playback.

});

}

• Prompt users to add your mobile site to the homescreen on Android devices. This will automatically give your application unmuted autoplay privileges.

Developer Recommendations: Web Audio API

The Web Audio API will be included in the Autoplay policy with M70 (October 2018). Generally, in Chrome developers can no longer assume that audio is allowed to play when a user first arrives at a site, and should assume that playback may be blocked until a user first interacts with the site through a user activation (a click or a tap). Any attempt to create an audioContext before that time may result in a suspended audioContext that will have to be explicitly switched to running after a user activation.

Developers who write games, WebRTC applications, or other websites that use the Web Audio API should call context.resume() after the first user gesture (e.g. a click, or tap). For example:

// Resume playback when user interacted with the page.

document.querySelector('button').addEventListener('click', function() {

context.resume().then(() => {

console.log('Playback resumed successfully');

});

});

Web Audio API developers can detect whether or not autoplay is allowed by creating a new AudioContext and then checking its state to see whether it is running (allowed) or suspended (blocked).

Depending upon the site, it may make sense to add additional user interface elements (such as a ‘play’ button in front of a game, or an ‘unmute’ button in some other cases), to explicitly capture a user gesture. This can either be done prior to creating AudioContext, or afterwards with a call to resume() upon click.

IFrame embedded content

Embedded content in a cross-origin IFrame needs to have permission to autoplay delegated to it, otherwise the audioContext will never be allowed to run.

Developers that host IFrames with content inside them (e.g. game hosting sites) can enable audio for that content without requiring the underlying content to change any code, by doing the following:

If the content is in a cross-origin IFrame, ensure that the IFrame includes
the attribute allow="autoplay"

Ensure that before the embedded content loads and runs, the site captures a
user gesture (e.g. prompt for a click or a tap)

Developers can find more details about specific code changes, and debugging tips here.

Web Audio API FAQs

Why is the Web Audio API part of the autoplay policy? Users don’t like to
click on a link and have sound played automatically that they weren’t
expecting. The Web Audio API produces sound, so it must be included in the
autoplay policy to ensure consistency across all web experiences.

Wait, didn’t you launch the autoplay policy for Web Audio API in M66? Yes,
briefly, but we reverted the change about a week later. We’re always working
to improve things for users and developers, but in this case we did not do
an effective job of communicating the change to developers using the Web
Audio API. We are moving the launch to October 2018 to give those developers
more time to prepare. If you develop web games, WebRTC applications, or
other web experiences with sound please see the developer recommendations.

Release Schedule

General FAQs

• What is the difference between this and Chrome’s enforcement of the better ad standard? The current better ad standard states that sites cannot embed stand-alone ads with unmuted audio. This standard does not apply to content integral to the page (e.g., video of a news article that goes along with the text). The autoplay policy is applicable to all video content regardless of its content.
• What is the MEI threshold and how will it apply to my site? We are still working on the implementation and don’t have any data yet on what the threshold will be or how that will impact individual sites. Our general guidance is if your site offers video content exclusively, assume that autoplay will work. If it has mixed content, assume it won’t unless users interact with the site in some way.
• Can my site be exempted from the policy? Unfortunately, Chrome cannot provide any exceptions to the autoplay policy.
• What counts as "user interaction on the domain?" Any click on the document itself (this excludes scrolling) will count as user interaction.
• Will autoplay work if a user leaves my site after watching video and returns later in a browsing session. Assuming the MEI threshold hasn't been met, autoplay will not work in that context. The user interaction requirement only applies to contiguous navigations.
• Will gestures and/or MEI score apply across tabs/windows? If the user opens a link in a new tab via context menu, yes, the user gesture will be counted and the MEI will reflect any views on the new tab.
• How can I view my own MEI scores? Navigate to chrome://media-engagement to see your personal scores. Individual or average scores will not be made available at this time.

More information

Autoplay policy summary presentation

Autoplay design document

Media engagement index (MEI) design document

Autoplay Policy Changes (developers.google.com)

DOMException: The play() request was interrupted (developers.google.com)