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

The addFromURI() method of the SpeechGrammarList interface takes a grammar present at a specific URI and adds it to the SpeechGrammarList as a new SpeechGrammar object.

Note that some speech recognition services may support built-in grammars that can be specified by URI.






A DOMString representing the URI of the grammar to be added.
weight Optional
A float representing the weight of the grammar relative to other grammars present in the SpeechGrammarList. The weight means the importance of this grammar, or the likelihood that it will be recognized by the speech recognition service. The value can be between 0.0 and 1.0; If not specified, the default used is 1.0.


var grammar = '#JSGF V1.0; grammar colors; public <color> = aqua | azure | beige | bisque | black | blue | brown | chocolate | coral | crimson | cyan | fuchsia | ghostwhite | gold | goldenrod | gray | green | indigo | ivory | khaki | lavender | lime | linen | magenta | maroon | moccasin | navy | olive | orange | orchid | peru | pink | plum | purple | red | salmon | sienna | silver | snow | tan | teal | thistle | tomato | turquoise | violet | white | yellow ;'
var recognition = new SpeechRecognition();
var speechRecognitionList = new SpeechGrammarList();
speechRecognitionList.addFromString(grammar, 1);
recognition.grammars = speechRecognitionList;

speechRecognitionList.addFromURI('http://www.example.com/grammar.txt'); // adds a second grammar to the list.


Specification Status Comment
Web Speech API
The definition of 'addFromURI()' in that specification.

Browser compatibility

BCD tables only load in the browser

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