AssemblyAI Speech-to-Text (Universal) vs ElevenLabs Scribe Speech to Text API

AssemblyAI Speech-to-Text (Universal)

OpenAPI 3.1 file with typed inputs and error responses on every operation. Two outages of an hour or more in the last 90 days, on 31 July and 16 September 2026.

ElevenLabs Scribe Speech to Text API

$0.22 an hour for batch with 90+ languages and diarisation to 32 speakers. Audio may be used for training unless the account opts out, and the opt-out isn't retroactive.

AssemblyAI Speech-to-Text (Universal)

1. Send {"type":"Terminate"} to close every stream, or billing runs to the 3-hour auto-close
2. Use speech_models (plural). The singular speech_model now returns 400 for current model names
3. Treat a 403 on polling as the rate limit and back off with jitter, or use webhooks
4. Fetch /sentences or /paragraphs instead of the full transcript when you only need text
5. Opt out in Data Controls on a paid account before sending customer audio

ElevenLabs Scribe Speech to Text API

1. Create a key restricted to speech-to-text with a credit quota and an expiry
2. Use source_url for hosted files instead of downloading and re-uploading
3. Set webhook=true for long files so the call doesn't block
4. Back off exponentially on any of the three 429 codes
5. Opt out under Data use before sending customer audio. It only covers later uploads