Cartesia vs Sesame
A side-by-side comparison of Cartesia and Sesame, two Voice tools, drawn from Ignaite's continuously-verified listings.
Compared from listings verified as of
At a glance
| Attribute | Cartesia | Sesame |
|---|---|---|
| Category | Voice | Voice |
| Pricing (differs) | FREEMIUM | FREE |
| License (differs) | Proprietary | Open source |
| Deployment | Cloud | Cloud |
| Platforms (differs) | API | Web |
| Model support (differs) | Single model (proprietary) | Self-contained (on-device) |
| Vendor (differs) | Cartesia | Sesame |
The honest brief
Cartesia
State-space Sonic models hit sub-100ms first audio — the latency floor for real-time voice agent loops.
- Streaming over WebSocket for fast first audio
- State-space architecture, not transformer
- Streaming-first WebSocket protocol depth
- Cost-competitive at scale
- Long-form expressive texture trails ElevenLabs
- Fewer voices than ElevenLabs catalog
- API-only, no end-user app
Sesame
Open-sourced its CSM-1B voice model under Apache 2.0 while keeping the viral Maya/Miles companions a hosted demo.
- Open Apache-2.0 CSM-1B base model
- Lifelike, natural conversational pacing
- Free real-time web demo
- Founder pedigree (Oculus co-creator)
- Demo only; no production API yet
- Companions not self-hostable
- Early-stage product