MediaStreamConstraints

The MediaStreamConstraints dictionary is used when calling getUserMedia() to specify what kinds of tracks should be included in the returned MediaStream, and, optionally, to establish constraints for those tracks' settings.

To learn more about how constraints work, see Capabilities, constraints, and settings.

Properties

Some combination—but not necessarily all—of the following properties will exist on the object.

Track constraints

audio

Either a Boolean (which indicates whether or not an audio track is requested) or a MediaTrackConstraints object providing the constraints which must be met by the audio track included in the returned MediaStream. If constraints are specified, an audio track is inherently requested.

video

Either a Boolean (which indicates whether or not a video track is requested) or a MediaTrackConstraints object providing the constraints which must be met by the video track included in the returned MediaStream. If constraints are specified, a video track is inherently requested.

Security

peerIdentity

A DOMString identifying the peer who has sole access to the stream. If this property is specified, only the indicated peer can receive and use the stream. Streams isolated in this way can only be displayed in a media element (<audio> or <video>) where the content is protected just as if CORS cross-origin rules were in effect.

Browser compatibility

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	WebView Android	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet
MediaStreamConstraints	53	≤79	38	No	Yes	11	53	53	38	Yes	11	6.0
audio	Yes	≤79	38	No	Yes	11	Yes	Yes	38	Yes	11	Yes
video	Yes	≤79	38	No	Yes	11	Yes	Yes	38	Yes	11	Yes

See also

• MediaDevices.getUserMedia()
• MediaStreamTrack.getConstraints()
• MediaStreamTrack.applyConstraints()
• MediaDevices.getSupportedConstraints()
• MediaTrackSupportedConstraints
• MediaStreamTrack.getSettings()