The MediaRecorder() constructor creates a new MediaRecorder object.


var m = new MediaRecorder(stream, options);


The MediaStream that will be recorded (generated, for example, from a getUserMedia.)

options Optional

A dictionary object that can contain the following properties:

  • mimeType: The mime type you want to use as the recording container for the new MediaRecorder. Applications can check in advance if this mimeType by calling MediaRecorder.isMimeTypeSupported().
  • audioBitsPerSecond: The chosen bitrate for the audio component of the media.
  • videoBitsPerSecond: The chosen bitrate for the video component of the media.
  • bitsPerSecond: The chosen bitrate for the audio and video components of the media. This can be specified instead of the above two properties. If this is specified along with one or the other of the above properties, this will be used for the one that isn't specified.

Note: If bits per second values are not specified for video and/or audio, the default adopted for video is 2.5Mbps, while the audio default is adaptive, dependant on the sample rate and number of channels.


<code class="language-html">

if (navigator.getUserMedia) {
  console.log('getUserMedia supported.');

  var constraints = { audio: true, video: true };
  var chunks = [];

  </code>var onSuccess = function(stream) {
    var options = {
      audioBitsPerSecond : 128000,
      videoBitsPerSecond : 2500000,
      mimeType : 'video/mp4'
    var mediaRecorder = new MediaRecorder(stream,options);
    m = mediaRecorder;



Specification Status Comment
MediaStream Recording Working Draft Initial definition

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 47 25.0 (25.0) No support No support No support
options object No support 43.0 (43.0) No support No support No support
Feature Android Android Webview Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile Chrome for Android
Basic support No support 47 25.0 (25.0) 1.3[1] No support No support No support 47

[1] The initial Firefox OS implementation only supported audio recording.

See also


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

API audio Audio Constructor Media Capture MediaRecorder Reference Video video