Official documentation
SpeechRecognition: available() static method
MDN Web Docs (Mozilla), 2026
Read the originalRead on October 17, 2026
- What it is
- MDN's reference page for the available() method, which checks whether speech recognition languages are supported, and whether their on-device language packs are installed when processLocally is true. It includes a worked example of installing a language pack.
- How much weight it carries
- Maintained by Mozilla and reviewed against the Web Speech API specification. The page is marked experimental, so the behavior may change between browser versions.
Facts taken from this source
- When a page sets processLocally to true but the correct on-device language pack is not installed, start() fails with a language-not-supported error.
“If you run the start() method after specifying processLocally = true but the correct language pack isn't installed, the function call will fail with a language-not-supported error.” (Examples: Checking on-device availability and installing language packs)