Adds the charLength attribute to the SpeechSynthesisEvent in the Web Speech API, which is fired every time a word is spoken in text to speech applications. The charLength length allows developers to get the length, in characters, of the word that is about to be spoken.


Currently, developers resort to third-party libraries or error-prone, self-rolled code for getting word length in text to speech applications. OS text to speech engines already expose this functionality, so this feature will reduce code bloat and complexity for web developers if we expose this functionality to them.



Specification link

Final published standard: Recommendation, Living Standard, Candidate Recommendation, or similar final form

Status in Chromium


In development (tracking bug)

Consensus & Standardization

After a feature ships in Chrome, the values listed here are not guaranteed to be up to date.

  • No signal
  • No signal
  • Positive


Search tags

text-to-speech, accessibility, education, speechsynthesis,

Last updated on 2022-01-21