AssemblyAI

A speech intelligence API that goes beyond basic transcription. AssemblyAI provides developers with accurate speech-to-text alongside powerful audio understanding features — including summarization, sentiment analysis, topic detection, and PII redaction — all through a simple REST API.

• Speech-to-text — highly accurate transcription with speaker labels and timestamps • LeMUR — apply LLMs to your transcripts for summaries, Q&A, and action items • Sentiment analysis — detect emotional tone throughout audio content • Topic detection — automatically identify key subjects discussed in recordings • PII redaction — automatically remove sensitive information from transcripts • Real-time streaming — sub-second latency for live transcription use cases

Pay-as-you-go from $0.37/hour. Free tier with 100 hours included.