This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The readyState read-only property of the MediaSource interface returns an enum representing the state of the current MediaSource. The three possible values are:

  • closed: The source is not currently attached to a media element.
  • open: The source is attached to a media element and ready to receive SourceBuffer objects.
  • ended: The source is attached to a media element but the stream has been ended via a call to MediaSource.endOfStream().

Syntax

var myReadyState = mediaSource.readyState;

Value

A DOMString.

Example

The following snippet is from a simple example written by Nick Desaulniers (view the full demo live, or download the source for further investigation.)

if ('MediaSource' in window && MediaSource.isTypeSupported(mimeCodec)) {
  var mediaSource = new MediaSource;
  //console.log(mediaSource.readyState); // closed
  video.src = URL.createObjectURL(mediaSource);
  mediaSource.addEventListener('sourceopen', sourceOpen);
} else {
  console.error('Unsupported MIME type or codec: ', mimeCodec);
}

function sourceOpen (_) {
  //console.log(this.readyState); // open
  var mediaSource = this;
  var sourceBuffer = mediaSource.addSourceBuffer(mimeCodec);
  fetchAB(assetURL, function (buf) {
    sourceBuffer.addEventListener('updateend', function (_) {
      mediaSource.endOfStream();
      video.play();
      //console.log(mediaSource.readyState); // ended
    });
    sourceBuffer.appendBuffer(buf);
  });
};

Specifications

Specification Status Comment
Media Source Extensions
The definition of 'readyState' in that specification.
Recommendation Initial definition.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung Internet
Basic support
Experimental
Chrome Full support 31
Full support 31
No support 23 — 31
Prefixed
Prefixed Requires the vendor prefix: -webkit-
Edge Full support 12Firefox Full support 42
Full support 42
No support 25 — 42
Notes Disabled
Notes Limited support to a whitelist of sites, for example YouTube, Netflix, and other popular streaming sites. The whitelist was removed when Media Source Extensions was enabled by default in Firefox 42.
Disabled From version 25 until version 42 (exclusive): this feature is behind the media.mediasource.enabled preference. To change preferences in Firefox, visit about:config.
IE Full support 11
Notes
Full support 11
Notes
Notes Only works on Windows 8+.
Opera Full support 15Safari Full support 8WebView Android Full support 4.4.3Chrome Android Full support 33Edge Mobile Full support YesFirefox Android Full support 41Opera Android Full support 30Safari iOS No support NoSamsung Internet Android Full support Yes

Legend

Full support  
Full support
No support  
No support
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.
See implementation notes.
See implementation notes.
User must explicitly enable this feature.
User must explicitly enable this feature.
Requires a vendor prefix or different name for use.
Requires a vendor prefix or different name for use.

See also

Document Tags and Contributors

Contributors to this page: fscholz, libbymc, chrisdavidmills
Last updated by: fscholz,