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

The emma read-only property of the SpeechRecognitionEvent interface returns an Extensible MultiModal Annotation markup language (EMMA) — XML — representation of the result.

Note: EMMA is defined in the specification EMMA: Extensible MultiModal Annotation markup language. You can see muliple EMMA examples in the spec.


var myEmma = event.emma;


A valid XML document. The exact contents can vary across user agents and recognition engines, but all supporting implementations will expose a valid XML document complete with an EMMA namespace. If the speech recognition system does not supply EMMA data then the user agent will return null.


recognition.onresult = function(event) {
  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 'emma' in that specification.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support33 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 ?

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: ExE-Boss, chrisdavidmills
Last updated by: ExE-Boss,