SpeechGrammar

Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

The SpeechGrammar interface of the Web Speech API represents a set of words or patterns of words for the recognition service to recognize.

Grammar is defined using JSpeech Grammar Format (JSGF).

Note: The concept of grammar has been removed from the Web Speech API. Related features remain in the specification and are still recognized by supporting browsers for backwards compatibility, but they have no effect on speech recognition services.

Constructor

SpeechGrammar(): Creates a new SpeechGrammar object.

Instance properties

SpeechGrammar.src: Sets and returns a string containing the grammar from within in the SpeechGrammar object instance.
SpeechGrammar.weight Optional: Sets and returns the weight of the SpeechGrammar object.

Examples

const 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 ;";
const recognition = new SpeechRecognition();
const speechRecognitionList = new SpeechGrammarList();
speechRecognitionList.addFromString(grammar, 1);
recognition.grammars = speechRecognitionList;

console.log(speechRecognitionList[0].src); // should return the same as the contents of the grammar variable
console.log(speechRecognitionList[0].weight); // should return 1 - the same as the weight set in addFromString.

Specifications

Specification
Web Speech API # speechreco-speechgrammar

Browser compatibility

	desktop					mobile
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on iOS	Samsung Internet	WebView Android	WebView on iOS
`SpeechGrammar` Deprecated	Chrome – Full support Chrome 25 (Release date: 2013-02-21) prefix prefix Implemented with the vendor prefix: webkit	Edge – Full support Edge 79 (Release date: 2020-01-15) prefix prefix Implemented with the vendor prefix: webkit	Firefox – No support Firefox 142 (Release date: 2025-08-19) prefix , disabled prefix Implemented with the vendor prefix: webkit disabled From version 142 users must explicitly set the `media.webspeech.recognition.enable` preference to `true`. To change preferences in Firefox, visit about:config. Firefox – No support Firefox 142 (Release date: 2025-08-19) disabled disabled From version 142 users must explicitly set the `media.webspeech.recognition.enable` preference to `true`. To change preferences in Firefox, visit about:config.	Opera – Full support Opera 15 (Release date: 2013-07-02) prefix prefix Implemented with the vendor prefix: webkit	Safari – No support Safari footnote No support	Chrome Android – Full support Chrome Android 25 (Release date: 2013-02-27) prefix prefix Implemented with the vendor prefix: webkit	Firefox for Android – No support Firefox for Android footnote No support	Opera Android – Full support Opera Android 14 (Release date: 2013-05-21) prefix prefix Implemented with the vendor prefix: webkit	Safari on iOS – No support Safari on iOS footnote No support	Samsung Internet – Full support Samsung Internet 1.5 (Release date: 2013-09-25) prefix prefix Implemented with the vendor prefix: webkit	WebView Android – No support WebView Android footnote No support	WebView on iOS – No support WebView on iOS footnote No support
`SpeechGrammar()` constructor Deprecated Non-standard	Chrome – Full support Chrome 25 (Release date: 2013-02-21) prefix prefix Implemented with the vendor prefix: webkit	Edge – Full support Edge 79 (Release date: 2020-01-15) prefix prefix Implemented with the vendor prefix: webkit	Firefox – No support Firefox 142 (Release date: 2025-08-19) prefix , disabled prefix Implemented with the vendor prefix: webkit disabled From version 142 users must explicitly set the `media.webspeech.recognition.enable` preference to `true`. To change preferences in Firefox, visit about:config. Firefox – No support Firefox 142 (Release date: 2025-08-19) disabled disabled From version 142 users must explicitly set the `media.webspeech.recognition.enable` preference to `true`. To change preferences in Firefox, visit about:config.	Opera – Full support Opera 15 (Release date: 2013-07-02) prefix prefix Implemented with the vendor prefix: webkit	Safari – No support Safari footnote No support	Chrome Android – Full support Chrome Android 25 (Release date: 2013-02-27) prefix prefix Implemented with the vendor prefix: webkit	Firefox for Android – No support Firefox for Android footnote No support	Opera Android – Full support Opera Android 14 (Release date: 2013-05-21) prefix prefix Implemented with the vendor prefix: webkit	Safari on iOS – No support Safari on iOS footnote No support	Samsung Internet – Full support Samsung Internet 1.5 (Release date: 2013-09-25) prefix prefix Implemented with the vendor prefix: webkit	WebView Android – No support WebView Android footnote No support	WebView on iOS – No support WebView on iOS footnote No support
`src` Deprecated	Chrome – Full support Chrome 25 (Release date: 2013-02-21) footnote Full support	Edge – Full support Edge 79 (Release date: 2020-01-15) footnote Full support	Firefox – No support Firefox 142 (Release date: 2025-08-19) disabled disabled From version 142 users must explicitly set the `media.webspeech.recognition.enable` preference to `true`. To change preferences in Firefox, visit about:config.	Opera – Full support Opera 15 (Release date: 2013-07-02) footnote Full support	Safari – No support Safari footnote No support	Chrome Android – Full support Chrome Android 25 (Release date: 2013-02-27) footnote Full support	Firefox for Android – No support Firefox for Android footnote No support	Opera Android – Full support Opera Android 14 (Release date: 2013-05-21) footnote Full support	Safari on iOS – No support Safari on iOS footnote No support	Samsung Internet – Full support Samsung Internet 1.5 (Release date: 2013-09-25) footnote Full support	WebView Android – No support WebView Android footnote No support	WebView on iOS – No support WebView on iOS footnote No support
`weight` Deprecated	Chrome – Full support Chrome 25 (Release date: 2013-02-21) footnote Full support	Edge – Full support Edge 79 (Release date: 2020-01-15) footnote Full support	Firefox – No support Firefox 142 (Release date: 2025-08-19) disabled disabled From version 142 users must explicitly set the `media.webspeech.recognition.enable` preference to `true`. To change preferences in Firefox, visit about:config.	Opera – Full support Opera 15 (Release date: 2013-07-02) footnote Full support	Safari – No support Safari footnote No support	Chrome Android – Full support Chrome Android 25 (Release date: 2013-02-27) footnote Full support	Firefox for Android – No support Firefox for Android footnote No support	Opera Android – Full support Opera Android 14 (Release date: 2013-05-21) footnote Full support	Safari on iOS – No support Safari on iOS footnote No support	Samsung Internet – Full support Samsung Internet 1.5 (Release date: 2013-09-25) footnote Full support	WebView Android – No support WebView Android footnote No support	WebView on iOS – No support WebView on iOS footnote No support

Tip: you can click/tap on a cell for more information.

Full support: Full support
No support: No support
: Non-standard. Check cross-browser support before using.
: Deprecated. Not for use in new websites.
: User must explicitly enable this feature.
: Requires a vendor prefix or different name for use.
: Has more compatibility info.