What is Cartesia?
Cartesia is a voice AI platform offering one API for speech generation, transcription and production voice agents. Its Sonic-3.6 text-to-speech model and Ink-2 speech-to-text model are built for low latency, so they can run in live conversation. The platform is aimed at developers and companies that need voice in their products.
In practice you can generate speech from text in many voices, including instant and professional voice cloning, transcribe audio, and deploy Managed Agents with Cartesia-provisioned phone numbers that handle inbound or outbound calls. Usage is billed through monthly credits for TTS and STT and per-minute rates for agent calls, with unlimited workspace seats on every plan.
Key features
- Real-time text-to-speech with the Sonic-3.6 model
- Speech-to-text transcription with the Ink-2 model
- Instant and professional voice cloning
- Managed voice agents with phone numbers
- Voice localization with added accents
- Concurrent request limits per plan
Who is it for
- Developers building voice features
- Companies running voice agents for customer calls
- Finance, healthcare and government organizations
- Startups building voice products
How to get started with Cartesia
- Create a free account on the Cartesia website
- Generate an API key in the developer dashboard
- Send your first TTS or STT request through the API
- You are building a voice application or real-time voice assistant
- You need one API for speech synthesis, transcription and telephone agents
- You want to clone a voice or localize it to different accents
- You need a no-code graphical interface, since the platform works only through the API
- You plan heavy agent usage on the free plan, because the 1 USD monthly limit runs out quickly
Pros and cons
- Built for low-latency live conversation
- One API covers speech generation, transcription and agents
- Unlimited workspace seats on every plan
- Agent calls are billed per minute on top of plan credits
- Some enterprise features (DPAs, BAAs, SSO) are only on custom Enterprise plans
Cartesia pricing
| Plan | Price | Includes |
|---|---|---|
| Free | 0 USD / month | 20K credits/month, $1 prepaid agents/month, ~27 min TTS, 2 concurrent requests |
| Pro | 5 USD / month | 100K credits/month, $5 prepaid agents/month, commercial license, instant voice cloning, ~133 min TTS, 3 concurrent requests |
| Startup | 49 USD / month | 1.25M credits/month, $49 prepaid agents/month, pro voice cloning, ~1,667 min TTS, 5 concurrent requests |
| Scale | 299 USD / month | 8M credits/month, $299 prepaid agents/month, priority support, high concurrency, ~10,667 min TTS, 15 concurrent requests |
Prices copied from Cartesia pricing, checked October 12, 2026. Currency as shown by the vendor; taxes may apply.
Is Cartesia free?
Yes, there is a free plan. Free plan: 20K credits per month, $1 prepaid agent dollars per month, access to Text to Speech and Speech to Text.
Featured in
Cartesia alternatives
| Tool | Price from | Free plan | Category |
|---|---|---|---|
 Hume AI | not listed | ? | APIs & models |
 MiniMax | 0.3 USD input / 1.2 USD output per M tokens | ? | APIs & models |
 Deepgram | 0.0048 USD/mo | trial | APIs & models |
 AssemblyAI | not listed | ? | APIs & models |
 Cline | not listed | yes | APIs & models |
 Ollama | 20 USD/mo | yes | APIs & models |
All alternatives to Cartesia →
FAQ
What is Cartesia used for?
Real-time text-to-speech, speech-to-text and voice agent API for developers building fast, live voice conversations.
Is Cartesia free?
Yes, there is a free plan. Free plan: 20K credits per month, $1 prepaid agent dollars per month, access to Text to Speech and Speech to Text.
How much does Cartesia cost?
The cheapest paid plan is 5 USD/mo (vendor pricing, October 12, 2026).
What are the best Cartesia alternatives?
Closest alternatives: Hume AI, MiniMax, Deepgram, AssemblyAI, Cline.
Data checked October 12, 2026 on the vendor website (cartesia.ai).