Cartesia Sonic
The fastest realistic AI voice — 90 ms latency, indistinguishable from human.
Visit Cartesia Sonic Free 10k chars/mo, Pro from $49/mo
What is Cartesia Sonic?
Cartesia's Sonic model is the lowest-latency realistic voice AI available. Built specifically for real-time conversational agents, phone systems, and live translation where every millisecond matters.
Key features
- 90 ms first-byte latency
- Voice cloning from 5 seconds of audio
- 15 languages
- Streaming API for real-time agents
- On-prem deployment option
Pros
- Lowest-latency realistic voice AI
- Quality matches ElevenLabs
- Streaming API is exceptionally good
Cons
- Pricier than alternatives for batch use
- Voice library smaller than ElevenLabs
Best for
Voice AI agentsLive translationInteractive voice systems
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