HTMLMediaElement: play() method
The HTMLMediaElement
play()
method attempts to begin playback of the media.
It returns a Promise
which is resolved when playback has been
successfully started.
Failure to begin playback for any reason, such as permission issues, result in the promise being rejected.
Syntax
js
play()
Parameters
None.
Return value
A Promise
which is resolved when playback has been started, or is
rejected if for any reason playback cannot be started.
Note: Browsers released before 2019 may not return a value from
play()
.
Exceptions
The promise's rejection handler is called with a DOMException
object
passed in as its sole input parameter (as opposed to a traditional exception being
thrown). Possible errors include:
NotAllowedError
DOMException
-
Provided if the user agent (browser) or operating system doesn't allow playback of media in the current context or situation. The browser may require the user to explicitly start media playback by clicking a "play" button, for example because of a Permissions Policy.
NotSupportedError
DOMException
-
Provided if the media source (which may be specified as a
MediaStream
,MediaSource
,Blob
, orFile
, for example) doesn't represent a supported media format.
Other exceptions may be reported, depending on browser implementation details, media player implementation, and so forth.
Usage notes
Although the term "autoplay" is usually thought of as referring to pages that
immediately begin playing media upon being loaded, web browsers' autoplay policies also
apply to any script-initiated playback of media, including calls to play()
.
If the user agent is configured not to allow automatic or
script-initiated playback of media, calling play()
will cause the returned
promise to be immediately rejected with a NotAllowedError
. Websites should
be prepared to handle this situation. For example, a site should not present a user
interface that assumes playback has begun automatically, but should instead update their
UI based on whether the returned promise is fulfilled or rejected. See the
example below for more information.
Note: The play()
method may cause the user to be asked
to grant permission to play the media, resulting in a possible delay before the
returned promise is resolved. Be sure your code doesn't expect an immediate response.
For even more in-depth information about autoplay and autoplay blocking, see our article Autoplay guide for media and Web Audio APIs.
Examples
This example demonstrates how to confirm that playback has begun and how to gracefully handle blocked automatic playback:
js
let videoElem = document.getElementById("video");
let playButton = document.getElementById("playbutton");
playButton.addEventListener("click", handlePlayButton, false);
playVideo();
async function playVideo() {
try {
await videoElem.play();
playButton.classList.add("playing");
} catch (err) {
playButton.classList.remove("playing");
}
}
function handlePlayButton() {
if (videoElem.paused) {
playVideo();
} else {
videoElem.pause();
playButton.classList.remove("playing");
}
}
In this example, playback of video is toggled off and on by the
async
playVideo()
function. It tries to play the video, and if successful sets
the class name of the playButton
element to "playing"
. If
playback fails to start, the playButton
element's class is cleared,
restoring its default appearance. This ensures that the play button matches the actual
state of playback by watching for the resolution or rejection of the
Promise
returned by play()
.
When this example is executed, it begins by collecting references to the
<video>
element as well as the <button>
used to toggle
playback on and off. It then sets up an event handler for the click
event
on the play toggle button and attempts to automatically begin playback by calling
playVideo()
.
You can try out or remix this example in real time on Glitch.
Specifications
Specification |
---|
HTML Standard # dom-media-play-dev |
Browser compatibility
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