Web/API/MediaRecorderErrorEvent/error

The read-only error property in the MediaRecorderErrorEvent interface is a DOMException object providing details about the exception that was thrown by a MediaRecorder instance.

When a MediaRecorderErrorEvent occurs, you can determine to some extent what went wrong by examining the error property within the MediaRecorderErrorEvent received by the MediaRecorder's error event handler, onerror.

Syntax

error = MediaRecorderErrorEvent.error;

Value

A DOMException describing the error represented by the event. The error's name property's value may be any exception that makes sense during the handling of media recording, including these specifically identified by the specification. The descriptions here are generic ones; you'll find more specific ones to various scenarios in which they may occur in the corresponding method references.

InvalidStateError: An operation was attempted in a context in which it isn't allowed, or a request has been made on an object that's deleted or removed.
NotSupportedError: A MediaRecorder couldn't be created because the specified options weren't valid. The message atttribute should provide additional information, if it exists.
SecurityError: The MediaStream is configured to disallow recording. This may be the case, for example, with sources obtained using getUserMedia() when the user denies permission to use an input device. This also happens when a MediaStreamTrack within the stream is marked as isolated due to the peerIdentity constraint on the source stream.
InvalidModificationError: The number of tracks on the stream being recorded has changed. You can't add or remove tracks while recording media.
UnknownError: A non-security related error occurred that cannot otherwise be categorized. Recording stops, the MediaRecorder's state becomes inactive, one last dataavailable event is sent to the MediaRecorder with the remaining received data, and finally a stop event is sent.

Examples

Basic error-handling example

This function creates and returns a MediaRecorder for a given MediaStream, configured to buffer data into an array and to watch for errors.

function recordStream(stream) {
  let recorder = null;
  let bufferList = [];

  try {
    recorder = new MediaRecorder(stream);
  } catch(err) {
    /* exception while trying to create the recorder; handle that */
  }

  recorder.ondataavailable = function(event) {
    bufferList.push(event.data);
  };

  recorder.onerror = function(event) {
    let error = event.error;
  };

  recorder.start(100);  /* 100ms time slices per buffer */
  return recorder;
}

Specifications

Specification	Status	Comment
MediaStream RecordingThe definition of 'MediaRecorderErrorEvent.error' in that specification.	Working Draft	Initial specification.

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
`error`	Chrome No support No Notes' No support No Notes' Notes' Uses a generic event with an `error` property.	Edge No support No Notes' No support No Notes' Notes' Uses a generic event with an `error` property.	Firefox Full support 57	IE No support No	Opera No support No Notes' No support No Notes' Notes' Uses a generic event with an `error` property.	Safari No support No	WebView Android No support No	Chrome Android No support No Notes' No support No Notes' Notes' Uses a generic event with an `error` property.	Firefox Android Full support 57	Opera Android No support No Notes' No support No Notes' Notes' Uses a generic event with an `error` property.	Safari iOS No support No	Samsung Internet Android No support No Notes' No support No Notes' Notes' Uses a generic event with an `error` property.

Legend

Full support: Full support
No support: No support
See implementation notes.': See implementation notes.