SpeechRecognition: maxAlternatives property

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

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

The default value is 1.

Value

A number representing the maximum returned alternatives for each result.

This code is excerpted from our Speech color changer example.

const recognition = new SpeechRecognition();
recognition.lang = "en-US";
recognition.interimResults = false;
recognition.maxAlternatives = 1;

// …

Specification
Web Speech API # dom-speechrecognition-maxalternatives

	desktop					mobile
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on iOS	Samsung Internet	WebView Android	WebView on iOS
`maxAlternatives`	Chrome – Full support Chrome 33 (Release date: 2014-02-20) footnote Full support	Edge – Full support Edge 79 (Release date: 2020-01-15) footnote Full support	Firefox – No support Firefox 143 (Release date: 2025-09-16) disabled disabled From version 143 users must explicitly set the `media.webspeech.recognition.enable` preference to `true`. To change preferences in Firefox, visit about:config.	Opera – Full support Opera 20 (Release date: 2014-03-04) footnote Full support	Safari – Full support Safari 14.1 (Release date: 2021-04-26) footnote Full support	Chrome Android – Full support Chrome Android 33 (Release date: 2014-02-26) footnote Full support	Firefox for Android – No support Firefox for Android footnote No support	Opera Android – Full support Opera Android 20 (Release date: 2014-03-06) footnote Full support	Safari on iOS – Full support Safari on iOS 14.5 (Release date: 2021-04-26) footnote Full support	Samsung Internet – Full support Samsung Internet 2 (Release date: 2014-10-17) footnote Full support	WebView Android – Full support WebView Android 4.4.3 (Release date: 2014-06-02) footnote Full support	WebView on iOS – Full support WebView on iOS 14.5 (Release date: 2021-04-26) footnote Full support

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