Amazon Transcribe vs AssemblyAI Speech-to-Text (Universal)

Amazon Transcribe

$0.006 a minute batch and $0.01 streaming in US East, with diarisation, custom vocabulary and language ID included. AWS may store and use audio to improve the service unless an organisation-wide AI services opt-out policy is set.

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.

Amazon Transcribe

1. Give every job a unique TranscriptionJobName. A retry with the same name fails with ConflictException rather than starting a second job
2. Batch is a job. Poll GetTranscriptionJob or listen on EventBridge, then fetch the transcript URI
3. Set OutputBucketName, because job records are deleted after 90 days
4. Back off on LimitExceededException. It arrives as a 400, not a 429
5. Set the organisation's AI services opt-out policy before sending customer audio

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