Listeners rate Cartesia's Sonic 3.6 above Breeze Blue's Breeze TTS 2.
ServiceNow, Decagon, and Quora run their production voice agents on Cartesia.
Voice quality
Listeners rate Sonic 3.6 above Breeze TTS 2
- Artificial Analysis plays listeners two clips of the same line without naming the model, and rates every model on the board the same way.
- Sonic 3.6 leads Breeze TTS 2, Breeze Blue's newest model, by more than 60 points.
Provider Voice Arena Elo
Higher is better
Speed
Sonic 3.6 generates speech more than three times as fast as Breeze TTS 2
- Artificial Analysis times every model on the board with the same harness, in characters generated per second.
- Generating well ahead of playback keeps a long turn from stalling mid-sentence.
Characters per second
Higher is better
Reasons why companies choose Cartesia over Breeze Blue
Human-like naturalness
Intonation, pacing, pronunciation, emotion, and audio quality that drive higher completion rates
Cartesia1291 EloBreeze Blue1228 EloOctober 2026
Speed
Headroom over playback, so a long turn never stalls mid-sentence.
Cartesia155.9 characters per secondBreeze Blue43.8 characters per secondOctober 2026
Frequently asked questions
How is the quality score measured?
It comes from Artificial Analysis, an independent benchmark. Listeners hear two clips of the same line without being told which model produced either, and pick the one they prefer. Sonic 3.6 rates above Breeze TTS 2, Breeze Blue's newest text to speech model.
How fast does Cartesia generate speech compared with Breeze Blue?
Artificial Analysis measures Sonic 3.6 at 155.9 characters per second and Breeze TTS 2 at 43.8, timed by the same harness.
Can I use my own voice with Cartesia?
Yes. An instant clone takes 10 seconds of audio and a professional clone takes 30 minutes, both self-serve on the public API.
How long does it take to switch from Breeze Blue?
One to two weeks for most teams. Cartesia is integrated into the major voice agent platforms and every model is on the public API, so there is no platform to move onto and nothing to unpick later.
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