Diarization - RunAnywhere Documentation

Diarization segments a recording by speaker. It answers “who spoke when”, not “what did they say”; pair it with transcription for both.

const result = await RunAnywhere.diarization.diarize(audio)

Options

Field	Meaning
`threshold`	How different two voices must be to count as separate speakers
`minimumDurationMs`	Ignore segments shorter than this
`mergeGapMs`	Join two segments from one speaker separated by less than this

mergeGapMs is the one to tune. Natural speech has pauses inside a turn, and without merging you get one speaker fragmented into a dozen segments.

Diarization inside transcription

For a transcript labelled by speaker rather than a separate segment list, ask the STT namespace instead:

const transcription = await RunAnywhere.stt.transcribe(audio, {
  diarization: true,
  maxSpeakers: 2,
})

Use the STT route when you want a readable transcript. Use the diarization namespace when you want timing, for example to drive a speaker timeline or to split a recording into per-speaker files.

Knowing the speaker count helps

maxSpeakers on the STT path, and a sensible threshold here, both improve accuracy a lot when you know how many people are in the room. Diarization over-segments when left to guess. Web has no streaming diarizer. Diarize a completed recording, or use the STT path with diarization: true for live labelling.