Deepgram vs Retell AI
A side-by-side comparison of capabilities, autonomy, integrations, and pricing to help you choose.
Short answer: choose Deepgram if you want voice ai infrastructure: speech-to-text, text-to-speech, and a voice agent api (Assistant, usage); choose Retell AI if you want platform to build, test, deploy, and monitor ai voice agents for calls (Autonomous agent, usage).
| Deepgram | Retell AI | |
|---|---|---|
| What it is | Voice AI infrastructure: speech-to-text, text-to-speech, and a voice agent API | Platform to build, test, deploy, and monitor AI voice agents for calls |
| Type | platform | platform |
| Autonomy | Assistant | Autonomous agent |
| Pricing | usage · $0.0048/min (Nova-3 streaming STT) | usage · $0.07/min voice engine (model + telephony billed on top); Enterprise from $8,000 |
| Best for | developers, enterprise | developers, smb, mid-market, enterprise |
| Deployment | saas, api, self-hosted, on-prem | saas, api |
| Modalities | voice, text, api, code | voice, text, api |
| Models | proprietary | model-agnostic, gpt, claude |
| Protocols | rest-api, function-calling | rest-api, function-calling |
| Integrations | Twilio, LiveKit, Vapi, Amazon SageMaker | Twilio, Telnyx, Vonage, ElevenLabs, PlayHT |
| Capabilities | 4 documented | 4 documented |
Deepgram
- +Mature, competitive STT (Nova) with low per-minute pricing and strong streaming
- +Rare true self-hosted, on-prem, and air-gapped options for regulated and government use
- +A single Voice Agent API collapses the STT-LLM-TTS stack
- -Infrastructure, not a finished product: you build the agent and UX yourself
- -The Voice Agent API is materially pricier, and connection-time billing can surprise
Retell AI
- +Provider-flexible: bring your own telephony, voices, and LLM, or use Retell's built-in carrier
- +Structured Conversation Flow Agents (nodes and transitions) give fine control alongside looser prompt-based agents
- +Usage-based pricing with no mandatory base subscription and free credits to start; built-in testing and monitoring
- -Advertised $0.07/min covers only the voice engine; LLM, telephony, and international add to real per-minute cost
- -Building reliable structured flows for complex calls takes meaningful human setup
Which should you choose?
Deepgram is voice ai infrastructure: speech-to-text, text-to-speech, and a voice agent api, best for developers, enterprise. Retell AI is platform to build, test, deploy, and monitor ai voice agents for calls, best for developers, smb, mid-market, enterprise. The right choice depends on the autonomy level you want, your existing integrations, and your budget, all compared above.