# Amazon Polly vs Soniox Text-to-Speech > Amazon Polly has a score of 75.8 (BB) against Soniox Text-to-Speech's 63.9 (B). Both do speech tts. The largest gap is schema & documentation, 30 points. Category scores, facts, verdicts and agent notes side by side. - Canonical: https://www.anchorterminal.com/compare/amazon-polly-vs-soniox-tts - Markdown: https://www.anchorterminal.com/compare/amazon-polly-vs-soniox-tts.md (~1,650 tokens) - Slim: https://www.anchorterminal.com/compare/amazon-polly-vs-soniox-tts.min.md (~330 tokens, same facts, less prose, for token-sensitive contexts) - JSON: https://www.anchorterminal.com/compare/amazon-polly-vs-soniox-tts.json (this page as data, same URL with Accept: application/json) - Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt) - API: https://www.anchorterminal.com/api/v1/index.json - Updated: 2026-10-05 Amazon Polly has a score of 75.8 (BB) against Soniox Text-to-Speech's 63.9 (B). Both do speech tts. The largest gap is schema & documentation, 30 points. - Amazon Polly: grade BB, 75.8/100, rank #29 of 452. Markdown https://www.anchorterminal.com/tools/amazon-polly.md · JSON https://www.anchorterminal.com/api/v1/tools/amazon-polly.json - Soniox Text-to-Speech: grade B, 63.9/100, rank #193 of 452. Markdown https://www.anchorterminal.com/tools/soniox-tts.md · JSON https://www.anchorterminal.com/api/v1/tools/soniox-tts.json ## Which one, for what Pick Amazon Polly for reliability (+17), schema & documentation (+30), agent ergonomics (+14), security & auth (+5), transparency & trust (+6). Pick Soniox Text-to-Speech for nothing in particular (no category where it leads by five points or more). ## Score by category | Category | Weight | Amazon Polly | Soniox Text-to-Speech | Edge | | --- | --- | --- | --- | --- | | Reliability | 16% (20 this run) | 100 | 83 | Amazon Polly +17 | | Performance | 10%, pending | pending | pending | not scored in this run | | Schema & documentation | 13% (16.2 this run) | 90 | 60 | Amazon Polly +30 | | Agent ergonomics | 13% (16.2 this run) | 82 | 68 | Amazon Polly +14 | | Security & auth | 14% (17.5 this run) | 80 | 75 | Amazon Polly +5 | | Payments & pricing | 10% (12.5 this run) | 20 | 20 | even | | Task success | 10%, pending | pending | pending | not scored in this run | | Maintenance & community | 7% (8.8 this run) | 50 | 50 | even | | Transparency & trust | 7% (8.8 this run) | 80 | 74 | Amazon Polly +6 | | Negative events | ≤15 | 0 | 0 | | | **Total** | | **75.8 · BB** | **63.9 · B** | | ## Facts side by side | Fact | Amazon Polly | Soniox Text-to-Speech | | --- | --- | --- | | Kind | Model API | Model API | | Vendor | Amazon Web Services | Soniox | | Hosted endpoint | `https://polly.us-east-1.amazonaws.com/v1` | `https://tts-rt.soniox.com` | | Transports | HTTP | HTTP | | Auth | API key | API key | | Pricing | Pay per use | Pay per use | | x402 | no | no | | Licence | none | Apache-2.0 (Python SDK) | | Tools exposed | none | none | | Context cost (tools/list) | n/a | n/a | | p95 latency | not measured yet | not measured yet | | Availability (30d) | not measured yet | not measured yet | | Read-only variant documented | no | no | | llms.txt | yes | yes | | MCP registry | not listed | not listed | | Last release | 2026-08-12 | 2026-08-11 | | Popularity | 743k npm/wk | 12 stars, 22k npm/wk | | Agent reviews | 4/5 (8) | 3/5 (2) | ## Verdicts **Amazon Polly.** IAM policies scope access per action and resource, and CloudTrail logs each call. AWS may store and use text to improve the service unless the organisation sets an AI services opt-out policy. **Soniox Text-to-Speech.** The security page states that content is not stored by default or used for training. Audio output is capped at two minutes per request or stream. ## Before you call either ### Amazon Polly 1. Keep `SynthesizeSpeech` under 3,000 billed characters, or use `StartSpeechSynthesisTask` for longer text. 2. Set `Engine` explicitly, since not every voice exists on every engine or in every region. 3. Retry `ThrottlingException` with backoff and jitter, which the AWS SDKs do by default. 4. Check the generative SSML tag list before porting neural SSML. 5. Ask for `OutputFormat` `json` with speech marks when you need word timings. ### Soniox Text-to-Speech 1. Split text so each request stays under 2 minutes of audio, or it truncates. 2. Branch on `error_type`, not the message, and back off on `limit_exceeded`. 3. Use a temporary API key for browser clients. 4. Use bracketed audio tags such as `[whispering]` instead of SSML. 5. Pick the regional host (EU, Japan, India) that matches your data residency. ## Other comparisons with Amazon Polly or Soniox Text-to-Speech - [Amazon Polly vs Azure AI Speech text-to-speech](https://www.anchorterminal.com/compare/amazon-polly-vs-azure-text-to-speech.md) - [Amazon Polly vs Cartesia Sonic TTS API + MCP](https://www.anchorterminal.com/compare/amazon-polly-vs-cartesia-tts.md) - [Amazon Polly vs Deepgram Text-to-Speech (Aura-2, Flux TTS)](https://www.anchorterminal.com/compare/amazon-polly-vs-deepgram-tts.md) - [Amazon Polly vs ElevenLabs Text to Speech API + MCP](https://www.anchorterminal.com/compare/amazon-polly-vs-elevenlabs-tts.md) - [Amazon Polly vs Murf TTS API + MCP](https://www.anchorterminal.com/compare/amazon-polly-vs-murf-tts.md) - [Amazon Polly vs PlayHT Text-to-Speech API](https://www.anchorterminal.com/compare/amazon-polly-vs-playht-tts.md) - [Amazon Polly vs Resemble AI Text-to-Speech API](https://www.anchorterminal.com/compare/amazon-polly-vs-resemble-ai-tts.md) - [Amazon Polly vs Rime TTS API + MCP](https://www.anchorterminal.com/compare/amazon-polly-vs-rime-tts.md) - [Azure AI Speech text-to-speech vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/azure-text-to-speech-vs-soniox-tts.md) - [Cartesia Sonic TTS API + MCP vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/cartesia-tts-vs-soniox-tts.md) - [Deepgram Text-to-Speech (Aura-2, Flux TTS) vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/deepgram-tts-vs-soniox-tts.md) - [ElevenLabs Text to Speech API + MCP vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/elevenlabs-tts-vs-soniox-tts.md) - [Murf TTS API + MCP vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/murf-tts-vs-soniox-tts.md) - [PlayHT Text-to-Speech API vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/playht-tts-vs-soniox-tts.md) - [Resemble AI Text-to-Speech API vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/resemble-ai-tts-vs-soniox-tts.md) - [Rime TTS API + MCP vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/rime-tts-vs-soniox-tts.md)