AssemblyAI

What it does

AssemblyAI is the developer's speech API: accurate transcription with speaker diarisation, sentiment, topic detection and real-time streaming. Products that need to understand audio build on it.

Pricing is transparent per hour with free credits to start. Reliability and model updates are the enterprise draw.

Standout features

• High-accuracy transcription API
• Speaker labels and sentiment
• Real-time streaming endpoints
• Audio intelligence add-ons

Best for