This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

The HTMLCanvasElement.captureStream() method returns a CanvasCaptureMediaStream that is a real-time video capture of the surface of the canvas.


<var>MediaStream</var> = <var>canvas</var>.captureStream(<var>framerate</var>);


framerate Optional
double that indicates the rate of capture of each frame. If not set, a new frame will be captured each time the canvas changes; if set to 0, one single frame will be captured.

Return Value

A reference to a MediaStream object.


// Find the canvas element to capture
var canvasElt = document.querySelector("canvas");

// Get the stream
var stream = canvasElt.captureStream(25); // 25 FPS

// Do things to the stream
// E.g. Send it to another computer using an RTCPeerConnection
//      pc is an RTCPeerConnection created elsewhere


Specification Status Comment
Media Capture from DOM Elements
The definition of 'HTMLCanvasElement.captureStream()' in that specification.
Editor's Draft Initial definition

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 51.0 43 (43) [1] No support 36.0 ?
Feature Android Android Webview Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support No support 51.0 51.0 43.0 (43) No support 38 ?

[1] In Firefox 41 and 42, this feature was disabled by default; set the preference canvas.capturestream.enabled to true to activate.

See also


© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.

Experimental HTMLCanvasElement Media Stream Method Reference Web