SpeechRecognition.maxAlternatives

The maxAlternatives property of the SpeechRecognition interface sets the maximum number of SpeechRecognitionAlternatives provided per SpeechRecognitionResult.

The default value is 1.

Syntax

var myMaxAlternativeNumber = mySpeechRecognition.maxAlternatives;
mySpeechRecognition.maxAlternatives = 2;

Value

A number representing the maximum returned alternatives for each result.

Examples

This code is excerpted from our Speech color changer example.

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;
//recognition.continuous = false;
recognition.lang = 'en-US';
recognition.interimResults = false;
recognition.maxAlternatives = 1;

...

Specifications

Browser compatibility

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

• Web Speech API