AI API Router Directory

AssemblyAI sells speech-to-text, speech understanding and voice agent APIs with pay-as-you-go hourly pricing and no credit card required to start. The free tier is published as up to 185 hours of pre-recorded transcription and up to 333 hours of streaming transcription. Published rates are $0.15 per hour for Universal-2 (99 languages) and $0.21 per hour for Universal-3.5 Pro (18 languages with native code switching), while realtime runs at $0.15 per hour for Universal-Streaming (English) and multilingual, or $0.45 per hour for Universal-3.5 Pro Realtime. The Voice Agent API is $4.50 per hour ($0.075 per minute) with every feature included, and the Dictation API is $0.62 per hour.

Free tier is stated as up to 185 hours of pre-recorded transcription and up to 333 hours of streaming transcription with no credit card required; valued at the lowest published pre-recorded rate (Universal-2 at $0.15 per hour) this is about $27.75, an estimate because AssemblyAI publishes hours rather than a USD credit (assemblyai.com/pricing, checked 2026-09-16).