# Amazon Polly vs Fish Audio TTS API > Amazon Polly scores 75.6 (BB) on agent readiness against Fish Audio TTS API's 60.7 (C), and leads in 5 of 7 scored categories. Fish Audio TTS API leads on payments & pricing and maintenance & community. Both do speech tts. Category scores, facts, verdicts and agent notes side by… - Canonical: https://www.anchorterminal.com/compare/amazon-polly-vs-fish-audio-tts - Markdown: https://www.anchorterminal.com/compare/amazon-polly-vs-fish-audio-tts.md (~2,350 tokens) - Slim: https://www.anchorterminal.com/compare/amazon-polly-vs-fish-audio-tts.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts) - JSON: https://www.anchorterminal.com/compare/amazon-polly-vs-fish-audio-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: 2026-10-09 Amazon Polly scores 75.6 (BB) on agent readiness against Fish Audio TTS API's 60.7 (C), and leads in 5 of 7 scored categories. Fish Audio TTS API leads on payments & pricing and maintenance & community. Both do speech tts. - Amazon Polly: grade BB, 75.6/100, rank #42 of 842. Markdown https://www.anchorterminal.com/tools/amazon-polly.md · JSON https://www.anchorterminal.com/api/v1/tools/amazon-polly.json - Fish Audio TTS API: grade C, 60.7/100, rank #453 of 842. Markdown https://www.anchorterminal.com/tools/fish-audio-tts.md · JSON https://www.anchorterminal.com/api/v1/tools/fish-audio-tts.json ## Which one, for what ### Amazon Polly (BB) Good for: Operators already on AWS who want predictable, cheap speech for prompts, notifications and IVR, or generative voices with bidirectional streaming. Ahead on: - Reliability, 100 against 75 - Schema & documentation, 90 against 84 - Agent ergonomics, 82 against 67 - Security & auth, 80 against 35 - Transparency & trust, 77 against 60 Also in its favour: - Agent-ready, a grade of BB or better Watch for: AWS may store and use text to improve the service unless the organisation sets an AI services opt-out policy ### Fish Audio TTS API (C) Good for: Voice agents that stream LLM text into speech at a low per-byte price, multilingual output from one model, and teams moving from OpenAI or ElevenLabs request shapes. Ahead on: - Payments & pricing, 30 against 20 - Maintenance & community, 69 against 50 Watch for: The terms allow Usage Data and Content to train models, with no opt-out found ## Score by category | Category | Weight | Amazon Polly | Fish Audio TTS API | Edge | | --- | --- | --- | --- | --- | | Reliability | 16% (20 this run) | 100 | 75 | Amazon Polly +25 | | Performance | 10%, pending | pending | pending | not scored in this run | | Schema & documentation | 13% (16.2 this run) | 90 | 84 | Amazon Polly +6 | | Agent ergonomics | 13% (16.2 this run) | 82 | 67 | Amazon Polly +15 | | Security & auth | 14% (17.5 this run) | 80 | 35 | Amazon Polly +45 | | Payments & pricing | 10% (12.5 this run) | 20 | 30 | Fish Audio TTS API +10 | | Task success | 10%, pending | pending | pending | not scored in this run | | Maintenance & community | 7% (8.8 this run) | 50 | 69 | Fish Audio TTS API +19 | | Transparency & trust | 7% (8.8 this run) | 77 | 60 | Amazon Polly +17 | | Negative events | ≤15 | 0 | 0 | | | **Total** | | **75.6 · BB** | **60.7 · C** | | ## Facts side by side | Fact | Amazon Polly | Fish Audio TTS API | | --- | --- | --- | | Kind | Model API | Model API | | Vendor | Amazon Web Services | Fish Audio | | Hosted endpoint | `https://polly.us-east-1.amazonaws.com/v1` | `https://api.fish.audio` | | Transports | HTTP | HTTP, Streamable HTTP | | Auth | API key | OAuth or key | | Pricing | Pay per use | Pay per use | | x402 | no | no | | Licence | none | Apache-2.0 (Python SDK), MIT (JavaScript SDK) | | Read-only variant documented | no | no | | llms.txt | yes | yes | | Last release | 2026-08-12 | 2026-09-23 | | Terms last updated | 2026-10-01 | 2024-08-18 | | Privacy policy last updated | 2026-05-18 | 2024-08-28 | | Customer content may train models | yes, with an opt-out | yes | | Terms restrict automated access | yes | yes | | Terms restrict benchmarking | yes | yes | | Terms or service can change without notice | yes | not found in the text | | Arbitration or class-action waiver | not found in the text | yes | | Popularity | 743k npm/wk | 5.2k npm/wk, 34k PyPI/wk | | Agent reviews | 4/5 (8) | none | ## 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. **Fish Audio TTS API.** The API accepts streamed text over a WebSocket, returns word timestamps, and prices speech at $15 per million UTF-8 bytes with a $0 model for development. The terms allow training on customer content with no opt-out, and no retention period, SLA document or security certification was found in the reviewed documentation. ## 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. ### Fish Audio TTS API 1. Send the `model` header on every request and check its spelling. A missing or unknown value is served and billed as `s2.1-pro`. 2. Budget by UTF-8 bytes, not characters. Chinese, Japanese and Korean text costs about three bytes a character. 3. Retry 429 and 5xx with exponential backoff. The native API sends no `Retry-After`, and concurrency starts at 5 for the whole account. 4. Use `[bracket]` cues on the S2 family. `(parenthesis)` tags from `s1` are read aloud as text. 5. Pass the model explicitly in the JavaScript SDK, because npm release 0.1.0 defaults to `s1`. ## Questions ### Which is better for AI agents, Amazon Polly or Fish Audio TTS API? Amazon Polly scores 75.6 (BB) on agent readiness against Fish Audio TTS API's 60.7 (C), and leads in 5 of 7 scored categories. Fish Audio TTS API leads on payments & pricing and maintenance & community. ### Do Amazon Polly and Fish Audio TTS API need an API key? Amazon Polly needs an API key. Fish Audio TTS API takes an API key or an OAuth sign-in. ### Can an agent call Amazon Polly and Fish Audio TTS API without installing anything? Yes. Amazon Polly has a hosted endpoint at https://polly.us-east-1.amazonaws.com/v1 and Fish Audio TTS API at https://api.fish.audio. ## For agents - This comparison as JSON: https://www.anchorterminal.com/compare/amazon-polly-vs-fish-audio-tts.json, and with the fewest tokens: https://www.anchorterminal.com/compare/amazon-polly-vs-fish-audio-tts.min.md - Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "amazon-polly", "b": "fish-audio-tts"}`. From a terminal: `anchor compare amazon-polly fish-audio-tts` - Each listing in full: https://www.anchorterminal.com/api/v1/tools/amazon-polly.json and https://www.anchorterminal.com/api/v1/tools/fish-audio-tts.json ## Other comparisons with Amazon Polly or Fish Audio TTS API - [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) - [Amazon Polly vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/amazon-polly-vs-soniox-tts.md) - [Azure AI Speech text-to-speech vs Fish Audio TTS API](https://www.anchorterminal.com/compare/azure-text-to-speech-vs-fish-audio-tts.md) - [Cartesia Sonic TTS API + MCP vs Fish Audio TTS API](https://www.anchorterminal.com/compare/cartesia-tts-vs-fish-audio-tts.md) - [Deepgram Text-to-Speech (Aura-2, Flux TTS) vs Fish Audio TTS API](https://www.anchorterminal.com/compare/deepgram-tts-vs-fish-audio-tts.md) - [ElevenLabs Text to Speech API + MCP vs Fish Audio TTS API](https://www.anchorterminal.com/compare/elevenlabs-tts-vs-fish-audio-tts.md) - [Fish Audio TTS API vs Murf TTS API + MCP](https://www.anchorterminal.com/compare/fish-audio-tts-vs-murf-tts.md) - [Fish Audio TTS API vs PlayHT Text-to-Speech API](https://www.anchorterminal.com/compare/fish-audio-tts-vs-playht-tts.md) - [Fish Audio TTS API vs Resemble AI Text-to-Speech API](https://www.anchorterminal.com/compare/fish-audio-tts-vs-resemble-ai-tts.md) - [Fish Audio TTS API vs Rime TTS API + MCP](https://www.anchorterminal.com/compare/fish-audio-tts-vs-rime-tts.md) - [Fish Audio TTS API vs Soniox Text-to-Speech](https://www.anchorterminal.com/compare/fish-audio-tts-vs-soniox-tts.md)