MediaDevices.enumerateDevices()

The MediaDevices.enumerateDevices() method collects information about the media input and output devices available on the system.

Syntax

navigator.mediaDevices.enumerateDevices()
.then(function(MediaDeviceInfo) { ... })

Returns

Returns a Promise that will be fulfilled with an array of MediaDeviceInfo instances, which contain information on the available media input and output devices, if enumeration is successful.

Example

Here's an example of using mediaDevices.enumerateDevices().

if (!navigator.mediaDevices || !navigator.mediaDevices.enumerateDevices) {
  console.log("enumerateDevices() not supported.");
  return;
}
// List cameras and microphones.
navigator.mediaDevices.enumerateDevices()
.then(function(devices) {
  devices.forEach(function(device) {
    console.log(device.kind + ": " + device.label +
                " id = " + device.deviceId);
  });
})
.catch(function(err) {
  console.log(err.name + ": " + err.message);
});

This might produce:

videoinput: id = csO9c0YpAf274OuCPUA53CNE0YHlIr2yXCi+SqfBZZ8=
audioinput: id = RKxXByjnabbADGQNNZqLVLdmXlS0YkETYCIbg+XxnvM=
audioinput: id = r2/xw1xUPIyZunfV1lGrKOma5wTOvCkWfZ368XCndm0=

or if one or more MediaStreams are active or persistent permissions are granted:

videoinput: FaceTime HD Camera (Built-in) id=csO9c0YpAf274OuCPUA53CNE0YHlIr2yXCi+SqfBZZ8=
audioinput: default (Built-in Microphone) id=RKxXByjnabbADGQNNZqLVLdmXlS0YkETYCIbg+XxnvM=
audioinput: Built-in Microphone id=r2/xw1xUPIyZunfV1lGrKOma5wTOvCkWfZ368XCndm0=

Permissions

To use enumerateDevices() in an installable app (for example, a Firefox OS app), you need to specify one or both of the following fields inside your manifest file:

"permissions": {
  "audio-capture": {
    "description": "Required to capture audio using getUserMedia()"
  },
  "video-capture": {
    "description": "Required to capture video using getUserMedia()"
  }
}

See permission: audio-capture and permission: video-capture for more information.

Specifications

Browser compatibility

[1] Behind a flag.

Chrome and Opera compatibility

• This interface is available in Chrome and Opera through the adapter.js polyfill.

See also

• navigator.mediaDevices.getUserMedia
• WebRTC - the introductory page to the API
• MediaStream API - the API for the media stream objects
• Taking webcam photos - a tutorial on using getUserMedia() for taking photos rather than video.