1. Web
  2. Web APIs
  3. MediaRecorder
  4. requestData()

MediaRecorder: requestData() method

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨April 2021⁩.

The requestData() method of the MediaRecorder interface is used to raise a dataavailable event containing a Blob object of the captured media as it was when the method was called. This can then be grabbed and manipulated as you wish.

When the requestData() method is invoked, the browser queues a task that runs the following steps:

  1. If MediaRecorder.state is "inactive", raise a DOM InvalidState error and terminate these steps. If MediaRecorder.state is not "inactive", continue to the next step.
  2. Raise a dataavailable event containing a Blob of the currently captured data (the Blob is available under the event's data attribute.)
  3. Create a new Blob and place subsequently captured data into it.

Syntax

js
requestData()

Parameters

None.

Return value

None (undefined).

Exceptions

InvalidStateError DOMException

Thrown if the MediaRecorder is currently "inactive"; you cannot capture the recording if the MediaRecorder is not active.

Examples

js
captureMedia.onclick = () => {
  mediaRecorder.requestData();
  // makes snapshot available of data so far
  // ondataavailable fires, then capturing continues
  // in new Blob
};

Specifications

Specification
MediaStream Recording
# dom-mediarecorder-requestdata

Browser compatibility

See also

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