Cartesia vs Inworld AI
Cartesia's Sonic 3.6 rates higher than every Inworld AI model.
ServiceNow, Decagon, and Quora run their production voice agents on Cartesia. One model, 44 languages, first audio in under 90ms.
Voice quality
Cartesia rates first on independent blind listening tests
- Cartesia's Sonic 3.6 ranks first of the 94 models on Artificial Analysis's Provider Voice Arena.
- Every Inworld AI Realtime TTS model rates below it.
Provider Voice Arena Elo
Higher is better
August 2026
1282
1199
1187
1134
Reasons why companies choose Cartesia over Inworld AI
Sonic 3.6
Realtime TTS-2, Realtime TTS 1.5 Max, Realtime TTS 1.5 Mini
CartesiaInworld AI
Human-like naturalness
Intonation, pacing, pronunciation, emotion, and audio quality that drive higher completion rates
Cartesia1282 EloInworld AI1199 EloRealtime TTS 1.5 Max1187 EloRealtime TTS-21134 EloRealtime TTS 1.5 MiniAugust 2026
Languages
Comprehension and trust across a global customer base.
Cartesia44 production languages from one model, best-in-class quality on each oneInworld AI15 extensively evaluated languages; quality varies more on the restDeployment
Decides whether regulated teams can use it at all.
CartesiaOn-prem and air-gapped, already running at government, healthcare, and financial institutions, behind a 99.9% uptime SLAInworld AISLA, DPA, and data residency are Enterprise-tier onlyEnd-to-end stack
How many vendors it takes to run one call.
CartesiaTTS, STT, and Agents from one vendor, on one API. The only provider ranked first on both speech and transcriptionInworld AITTS, STT, and a realtime router
Frequently asked questions
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