Web Speech API: Unspoken Punctuation

at a glance

why it exists

Without unspoken punctuation, using speech-to-text for writing tasks requires the user to dictate punctuation explicitly: "Hello comma how are you period". This is unnatural and cognitively taxing. With unspokenPunctuation: true, the recognition engine infers punctuation from speech prosody, pauses, and language models — producing naturally punctuated text without explicit dictation. The feature is analogous to the "automatic punctuation" toggle available in many voice input apps, now accessible to web developers via the Speech Recognition API.

the attribute

example

const recognition = new SpeechRecognition();
recognition.continuous = true;
recognition.interimResults = true;
recognition.lang = "en-US";

// Enable automatic punctuation insertion
recognition.unspokenPunctuation = true;

recognition.onresult = (event) => {
  const last = event.results[event.resultIndex];
  const transcript = last[0].transcript;
  // Transcript now includes inferred commas, periods, etc.
  // "Hello, how are you? I am fine." — punctuation added automatically
  document.getElementById("output").textContent = transcript;
};

recognition.start();

With explicit language for better punctuation inference

const recognition = new SpeechRecognition();
recognition.lang = "en-US";
recognition.unspokenPunctuation = true;
recognition.continuous = true;

// The recognition engine uses language-model punctuation inference
// Output example: "I'll be there at 3:00. See you then."
// Instead of: "i'll be there at 3 00 see you then"

browser support

see also

• Web Speech API specification
• chromestatus: Web Speech API: Unspoken Punctuation
• chrome-platform-showcase: demos