Cartesia vs Vapi
A side-by-side comparison of capabilities, autonomy, integrations, and pricing to help you choose.
Short answer: choose Cartesia if you want low-latency voice ai models and a platform for real-time voice agents (Assistant, freemium); choose Vapi if you want developer platform for voice ai agents that handle phone calls (Supervised agent, usage).
| Cartesia | Vapi | |
|---|---|---|
| What it is | Low-latency voice AI models and a platform for real-time voice agents | Developer platform for voice AI agents that handle phone calls |
| Type | platform | platform |
| Autonomy | Assistant | Supervised agent |
| Pricing | freemium · Free (20K credits/mo); Pro $5/mo | usage · $0.05/min platform fee + model costs at cost |
| Best for | developers, enterprise | developers, smb, mid-market, enterprise |
| Deployment | saas, api, self-hosted, on-prem | saas, api |
| Modalities | text, voice, api, code | voice, text, api |
| Models | proprietary | model-agnostic, gpt, claude, gemini |
| Protocols | rest-api, function-calling | rest-api, function-calling, mcp |
| Integrations | LiveKit, Twilio, Pipecat, Vapi | Twilio, Deepgram, ElevenLabs, OpenAI, Anthropic, Google |
| Capabilities | 4 documented | 4 documented |
Cartesia
- +Genuinely differentiated state-space-model tech with best-in-class latency and on-device efficiency
- +Full stack (TTS, STT, cloning, and the Line agent platform) plus deep ecosystem integrations and self-hosted/VPC options
- +Strong technical credibility and capital, including NVIDIA backing
- -Younger and less battle-tested than ElevenLabs and Deepgram; the Line agent platform is barely a year old
- -Closed, proprietary models (no open weights for production Sonic/Ink), creating lock-in
Vapi
- +Deep modularity and control: swap any STT/LLM/TTS provider, bring your own keys and models, fine-tune thousands of config points
- +Low latency at scale with enterprise reliability features (model fallbacks, SOC 2/HIPAA/PCI), validated by large production deployments
- +Transparent usage pricing with at-cost model pass-through and a low platform fee, plus open-source SDKs and a CLI
- -Complexity and steep setup; the no-code builder is limited and non-engineering teams face significant manual configuration
- -Costs can stack unpredictably: the per-minute fee is on top of separately billed provider costs and add-ons
Which should you choose?
Cartesia is low-latency voice ai models and a platform for real-time voice agents, best for developers, enterprise. Vapi is developer platform for voice ai agents that handle phone 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.