Voice-agent developers who need very fast speech and quick voice cloning; a free monthly allowance makes it cheap to trial.
Kenning's take
What it does
Sonic 3 is Cartesia's real-time text-to-speech model, built for voice agents, with first audio in under 90 milliseconds. It picks up emotion from the text, supports tags such as laughter, clones a voice from about 10 seconds of audio and works in many languages, with the current Sonic-3.6 covering 44. Developers use it through Cartesia's API on free and paid plans.
- First audio in under 90ms
- Emotion read from the transcript and [laughter] tags
- Instant voice cloning from 10 seconds of audio
- 44 languages in Sonic-3.6
- Custom pronunciation dictionaries
Who it suits. Developers building voice agents, phone systems and narrated apps.
Key facts
- Category
- AI models
- Made by
- Cartesia
- Launched
- 2025
- How to get it
- through the Cartesia API and playground; also on Amazon SageMaker JumpStart
- Works on
- API, Web
- Free plan
- 20K credits a month on the Free plan
- API price
- credit-based; Pro's 100K credits give about 133 minutes of text-to-speech a month
Pricing
| Plan | Price | Billed |
|---|---|---|
| Pro | $5 | month |
| Startup | $49 | month |
| Scale | $299 | month |
FAQ
How fast is Sonic 3?
Cartesia says first audio arrives in under 90 milliseconds.
Is Sonic 3 free?
There is a free plan with 20,000 credits a month; paid plans start at $5 a month.
Can Sonic 3 clone a voice?
Yes, from about 10 seconds of audio.
Facts from the maker's own pages and the sources listed. Checked 2026-10-11.
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