Why isn't my iPhone transcribing?

Your iPhone stops transcribing for a handful of reasons: the language is not supported for transcription, the on-device speech model never downloaded, Dictation is switched off, or the feature you expect needs a newer iOS.

Voice message transcription in Messages requires a recent iOS and currently supports a limited set of languages, which is why audio messages sometimes show no transcript at all. Voice Memos transcripts have similar language limits.

Fixes in order: confirm Settings, General, Keyboard, Enable Dictation is on; check your language is supported for the feature; free up storage so the speech model can download; restart. If a specific voice memo will not transcribe, background noise or music is usually the reason.

For recordings Apple refuses, a voice memo to text converter gets the words out.