SpeechRecognitionAlternative: confidence property

Limited availability

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

The confidence read-only property of the SpeechRecognitionResult interface returns a numeric estimate of how confident the speech recognition system is that the recognition is correct.

Note: Mozilla's implementation of confidence is still being worked on — at the moment, it always seems to return 1.

Value

A number between 0 and 1.

Examples

This code is excerpted from our Speech color changer example.

recognition.onresult = (event) => {
  const color = event.results[0][0].transcript;
  diagnostic.textContent = `Result received: ${color}.`;
  bg.style.backgroundColor = color;
  console.log(`Confidence: ${event.results[0][0].confidence}`);
};