Web/API/MediaRecorder/onstart

The MediaRecorder.onstartevent handler (part of the MediaRecorder API) handles the start event, allowing you to run code in response to media recording being started by a MediaRecorder.

The start event is thrown as a result of the MediaRecorder.start() method being invoked. At this point, the data starts being gathered into a Blob.

Syntax

MediaRecorder.onstart = function(event) { ... }
MediaRecorder.addEventListener('start', function(event) { ... })

Example

...

  record.onclick = function() {
    mediaRecorder.start();
    console.log("recorder started");
  }

  mediaRecorder.onstart = function() {
    // do something in response to
    // recording being started
  }

...

Properties

None.

Specifications

Specification	Status	Comment
MediaStream RecordingThe definition of 'MediaRecorder.onstart' in that specification.	Working Draft	Initial definition

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`onstart`	Chrome Full support 49	Edge Full support 79	Firefox Full support 25	IE No support No	Opera Full support 36	Safari No support No	WebView Android Full support 49	Chrome Android Full support 49	Firefox Android Full support 25	Opera Android Full support 36	Safari iOS No support No	Samsung Internet Android Full support 5.0

Legend

Full support: Full support
No support: No support