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SpeechRecognitionAlternative

The SpeechRecognitionAlternative interface of the Web Speech API represents a single word that has been recognized by the speech recognition service.

Instance properties

SpeechRecognitionAlternative.transcript Read only

Returns a string containing the transcript of the recognized word.

SpeechRecognitionAlternative.confidence Read only

Returns a numeric estimate between 0 and 1 of how confident the speech recognition system is that the recognition is correct.

Examples

This code is excerpted from our Speech color changer example.

js

recognition.onresult = (event) => {
  // The SpeechRecognitionEvent results property returns a SpeechRecognitionResultList object
  // The SpeechRecognitionResultList object contains SpeechRecognitionResult objects.
  // It has a getter so it can be accessed like an array
  // The first [0] returns the SpeechRecognitionResult at position 0.
  // Each SpeechRecognitionResult object contains SpeechRecognitionAlternative objects
  // that contain individual results.
  // These also have getters so they can be accessed like arrays.
  // The second [0] returns the SpeechRecognitionAlternative at position 0.
  // We then return the transcript property of the SpeechRecognitionAlternative object
  const color = event.results[0][0].transcript;
  diagnostic.textContent = `Result received: ${color}.`;
  bg.style.backgroundColor = color;
};

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
SpeechRecognitionAlternative 33 79 No No No 14.1 4.4.3 33 No No 14.5 2.0
confidence 33 79 No No No 14.1 4.4.3 33 No No 14.5 2.0
transcript 33 79 No No No 14.1 4.4.3 33 No No 14.5 2.0

See also

© 2005–2023 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/SpeechRecognitionAlternative