This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The SpeechRecognitionEvent interface of the Web Speech API represents the event object for the result and nomatch events, and contains all the data associated with an interim or final speech recognition result.


SpeechRecognitionEvent also inherits properties from its parent interface, Event.

SpeechRecognitionEvent.emma Read only
Returns an Extensible MultiModal Annotation markup language (EMMA) — XML — representation of the result.
SpeechRecognitionEvent.interpretation Read only
Returns the semantic meaning of what the user said.
SpeechRecognitionEvent.resultIndex Read only
Returns the lowest index value result in the SpeechRecognitionResultList "array" that has actually changed.
SpeechRecognitionEvent.results Read only
Returns a SpeechRecognitionResultList object representing all the speech recognition results for the current session.


This code is excerpted from our Speech color changer example.

recognition.onresult = function(event) {
  // The SpeechRecognitionEvent results property returns a SpeechRecognitionResultList object
  // The SpeechRecognitionResultList object contains SpeechRecognitionResult objects.
  // It has a getter so it can be accessed like an array
  // The first [0] returns the SpeechRecognitionResult at position 0.
  // Each SpeechRecognitionResult object contains SpeechRecognitionAlternative objects that contain individual results.
  // These also have getters so they can be accessed like arrays.
  // The second [0] returns the SpeechRecognitionAlternative at position 0.
  // We then return the transcript property of the SpeechRecognitionAlternative object
  var color = event.results[0][0].transcript;
  diagnostic.textContent = 'Result received: ' + color + '.';
  bg.style.backgroundColor = color;


Specification Status Comment
Web Speech API
The definition of 'SpeechRecognitionEvent' in that specification.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support33 webkit 1 ? No No No No
emma33 webkit 1 ? No No No No
interpretation33 webkit 1 ? No No No No
resultIndex33 webkit 1 ? No No No No
results33 webkit 1 ? No No No No
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support Yes webkit 1 Yes webkit 1 ? No No No ?
emma Yes webkit 1 Yes webkit 1 ? No No No ?
interpretation Yes webkit 1 Yes webkit 1 ? No No No ?
resultIndex Yes webkit 1 Yes webkit 1 ? No No No ?
results Yes webkit 1 Yes webkit 1 ? No No No ?

1. You'll need to serve your code through a web server for recognition to work.

Firefox OS permissions

To use speech recognition in an app, you need to specify the following permissions in your manifest:

"permissions": {
  "audio-capture" : {
    "description" : "Audio capture"
  "speech-recognition" : {
    "description" : "Speech recognition"

You also need a privileged app, so you need to include this as well:

  "type": "privileged"

See also

Document Tags and Contributors

Contributors to this page: lucian95, sgiles, chrisdavidmills
Last updated by: lucian95,