Head to head
Amazon Polly vs Cartesia
As a text-to-speech API, Amazon Polly rates higher on the APIbenchmarks Index, 83.7 to 75.7, a 8-point gap. Here is how they compare on each criterion.
Criterion by criterion
| Criterion | Amazon Polly | Cartesia |
|---|---|---|
| Documentation & DX | ||
| Reliability | ||
| Ecosystem & SDKs | ||
| Accessibility | ||
| APIbenchmarks Index | 83.7 | 75.7 |
Specifications
| Amazon Polly | Cartesia | |
|---|---|---|
| Best for | TTS embedded in the AWS stack | Real-time TTS for voice agents |
| Free tier | 5M chars/mo, 12 months (Neural 1M) | 20k credits (~15-20 min audio) |
| Pricing | Per 1M characters | Per character (credits) |
| Official SDKs | 12 languages | 4 languages |
Is Amazon Polly better than Cartesia?
On the APIbenchmarks Index, Amazon Polly rates higher (83.7 vs 75.7). It leads on the four weighted criteria, but price is reported separately, so the best choice still depends on your budget.
Verdict in one line
Amazon Polly leads by 8 points (83.7 vs 75.7) and wins 3 of 4 criteria; Cartesia wins 1.
Winner by criterion
| Criterion |  Amazon Polly | Winner | |
|---|---|---|---|
| Documentation & DX | 82 | 80 | Amazon Polly |
| Reliability | 92 | 68 | Amazon Polly |
| Ecosystem & SDKs | 90 | 70 | Amazon Polly |
| Accessibility | 68 | 86 |
Choose Amazon Polly if… / choose Cartesia if…
Choose Amazon Polly if- →documentation & dx matters most to you (82 vs 80)
- →reliability matters most to you (92 vs 68)
- →ecosystem & sdks matters most to you (90 vs 70)
- →you need broad SDK coverage (12 official SDKs vs 4)
- →your use case matches its focus: tts embedded in the aws stack
- →accessibility matters most to you (86 vs 68)
- →your use case matches its focus: real-time tts for voice agents
Pricing side by side
Amazon Polly- Model
- Per 1M characters
- Free tier
- 5M chars/mo, 12 months (Neural 1M)
- Standard voices$4.00 / 1M characters
- Neural voices (NTTS)$16.00 / 1M characters
- Generative voices$30.00 / 1M characters
- Long-Form voices$100.00 / 1M characters
- Model
- Per character (credits)
- Free tier
- 20k credits (~15-20 min audio)
- Free$0/mo
- Pro$5/mo
- Startup$49/mo
- Scale$299/mo
- EnterpriseCustom
Vendor-published pricing, verified 2026-06-27 (Amazon Polly) and 2026-06-27 (Cartesia).
SDK and language coverage
Both · 1
Python (Boto3)
Only Amazon Polly · 11
JavaJavaScript / Node.js.NET (C#)PHPRubyGoC++iOS (AWS Mobile SDK)Android (AWS Mobile SDK)AWS CLIHTTP / REST API
Only Cartesia · 3
JavaScript / TypeScript (official client)REST APIWebSocket API
Strengths and weaknesses
Amazon Polly- +Pay-as-you-go per-character pricing with no monthly platform fee and a sizable always-free Standard tier (5M chars/month)
- +Deep native integration with AWS (IAM, S3, CloudWatch, KMS) and powers Amazon Connect IVR
- +Broad coverage: 100+ voices across 40+ languages/variants, plus bilingual voices that switch language mid-sentence
- –Older Standard voices sound robotic/unnatural compared to modern neural TTS
- –Several head-to-head comparisons rate voice quality a step below Microsoft Azure
- –Premium engines are expensive (Long-Form $100/M, Generative $30/M), making costs unpredictable at scale
- +Class-leading latency for real-time voice, advertised ~40ms TTFB and measured fastest-tier P50 TTFA vs ElevenLabs and Deepgram in independent benchmarks
- +State-space-model architecture purpose-built for streaming, low-latency conversational audio rather than batch generation
- +Instant voice cloning from as little as 3-10 seconds of audio, plus higher-fidelity professional cloning
- –A developer API, not a business tool, no no-code workflow, helpdesk wiring, or agent-testing layer; you must build the surrounding system
- –Self-reported and reviewer-noted weakness in logging, observability, and troubleshooting tooling
- –Latency consistency is a concern: third-party tests show a wide inter-quartile range, so tail latency can approach the 300ms conversational threshold
Amazon Polly vs Cartesia: questions
- Which has better documentation, Amazon Polly or Cartesia?
- Amazon Polly scores higher on documentation and developer experience: 82 vs 80 out of 100.
- Which is more reliable, Amazon Polly or Cartesia?
- Amazon Polly scores higher on reliability: 92 vs 68 out of 100.
- Do Amazon Polly and Cartesia have a free tier?
- Amazon Polly: yes (5M chars/mo, 12 months (Neural 1M)). Cartesia: yes (20k credits (~15-20 min audio)).
- How are Amazon Polly and Cartesia priced?
- Amazon Polly: Per 1M characters. Cartesia: Per character (credits).
- Which has more official SDKs?
- Amazon Polly lists 12 official SDKs, Cartesia lists 4.