Cartesia vs Amazon Polly
Listeners rate Cartesia's Sonic 3.6 above every Amazon Polly engine.
ServiceNow, Decagon, and Quora run their production voice agents on Cartesia. One model, 44 languages, first audio in under 90ms.
Voice quality
Listeners rate Sonic 3.6 above every Polly engine
- 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 Polly Generative, Polly's highest-rated engine, by more than 200 points.
Provider Voice Arena Elo
Higher is better
Speed
Sonic 3.6 generates faster than Polly's two highest-rated engines
- Artificial Analysis times every model on the board with the same harness, in characters generated per second.
- Sonic 3.6 outpaces Polly Generative and Polly Long-form, so the voice listeners prefer is also the quicker one.
Characters per second
Higher is better
Reasons why companies choose Cartesia over Amazon Polly
Generative, Long-form, Neural, StandardHuman-like naturalness
Intonation, pacing, pronunciation, emotion, and audio quality that drive higher completion rates
Cartesia1276 EloAmazon Polly1064 EloPolly Generative1032 EloPolly Long-form892 EloPolly Neural829 EloPolly StandardSeptember 2026
Languages
Comprehension and trust across a global customer base.
Cartesia44 languages from one model, with native accentsAmazon PollyGenerative voices in 9 languagesCustom voices
How much audio it takes, and who is allowed to use one.
CartesiaInstant clone from 10 seconds, professional clone from 30 minutes, on the public APIAmazon PollyBrand Voice, a custom engagement with the Amazon Polly teamDeployment
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 SLAAmazon PollyGenerative voices in 10 AWS regionsEnd-to-end stack
How many products it takes to run one call.
CartesiaTTS, STT, and Agents from one vendor, on one APIAmazon PollyPolly for speech, with transcription and agents in separate AWS services
Frequently asked questions
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