AssemblyAI vs Retell AI
Side-by-side comparison of AssemblyAI and Retell AI: pricing, features, API access, and community ratings.
AssemblyAI is a speech-to-text and voice AI infrastructure provider with exceptional multilingual transcription (99 languages) and unlimited scaling, making it ideal for developers building custom voice applications that require accurate transcription, PII handling, and content analysis. Retell AI is purpose-built for automating phone conversations with ultra-low latency, featuring a no-code agent builder, outbound dialing campaigns, and built-in call quality assurance—optimized for businesses deploying voice agents at scale. Choose AssemblyAI if you need flexible voice-to-text building blocks for custom applications; choose Retell AI if you want a complete phone automation solution with minimal development effort.
AssemblyAI Voice AI infrastructure for builders — industry-leading speech-to-text and voice agent APIs | ||
|---|---|---|
| Category | Voice & speech | Voice & speech |
| Pricing | Freemium | Freemium |
| Starting price | ||
| Free tier | ||
| Audience | Technical | All audiences |
| API available | ||
| Open source | ||
| Self-hostable | ||
| Model provider | AssemblyAI (Universal-3 Pro, Universal-2, Universal-Streaming, Whisper-Streaming) | Multiple (OpenAI GPT, Anthropic Claude, Google Gemini, Custom LLM) |
| Founded | 2017 | |
| Headquarters | San Francisco, United States | |
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