The MediaDeviceInfo interface contains information that describes a single media input or output device.

The list of devices obtained by calling navigator.mediaDevices.enumerateDevices() is an array of MediaDeviceInfo objects, one per media device.

MediaDeviceInfo.deviceId Read only

Returns a string that is an identifier for the represented device that is persisted across sessions. It is un-guessable by other applications and unique to the origin of the calling application. It is reset when the user clears cookies (for Private Browsing, a different identifier is used that is not persisted across sessions).

MediaDeviceInfo.groupId Read only

Returns a string that is a group identifier. Two devices have the same group identifier if they belong to the same physical device — for example a monitor with both a built-in camera and a microphone.

MediaDeviceInfo.kind Read only

Returns an enumerated value that is either "videoinput", "audioinput" or "audiooutput".

MediaDeviceInfo.label Read only

Returns a string describing this device (for example "External USB Webcam").

MediaDeviceInfo.toJSON()

Returns a JSON representation of the MediaDeviceInfo object.

Here's an example that uses enumerateDevices() to get a list of devices.

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

This might produce:

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

or if one or more media streams are active, or if persistent permissions have been 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=

• WebRTC API
• navigator.mediaDevices.enumerateDevices()
• navigator.mediaDevices.getUserMedia()