AssemblyAI
Free trialLiveLast verified 27 Sept 2026
Speech-to-text for files and live audio in 99 languages, with speaker labels, subtitles and an LLM gateway.
Example request
curl -s https://api.assemblyai.com/v2/transcript -H "Authorization: $API_KEY"
Free tier, in plain English
Sign up without a card and get a starting allowance of up to 185 hours of file transcription or 333 hours of streaming. After that it's pay-as-you-go, from $0.15 an hour.
Alternatives in Speech
AudexumText-to-speech in 43 voices and 32 languages, plus speech-to-text transcription in 100+ languages.FreemiumCartesiaLow-latency text-to-speech over HTTP, SSE or WebSocket, plus speech-to-text and instant voice cloning.FreemiumDeepgramSpeech-to-text and text-to-speech transcription with streaming and pre-recorded audio, plus voice agents.Free trialElevenLabsText-to-speech in 70+ languages with 10,000+ voices, plus speech-to-text, voice cloning and dubbing.FreemiumFish AudioText-to-speech with emotion tags, instant voice cloning from short clips, and transcription, billed per byte.Freemium
All 12 Speech APIs →