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.
A number between 0 and 1.
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}`);
};