# Amazon Transcribe vs Cartesia Ink

> Amazon Transcribe scores 73.4 (BB) to Cartesia Ink's 67.9 (B) for speech-to-text. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/amazon-transcribe-vs-cartesia-ink-stt
- Markdown: https://www.anchorterminal.com/compare/amazon-transcribe-vs-cartesia-ink-stt.md (~2,700 tokens)
- Slim: https://www.anchorterminal.com/compare/amazon-transcribe-vs-cartesia-ink-stt.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/amazon-transcribe-vs-cartesia-ink-stt.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 Transcribe scores 73.4 (BB) on agent readiness against Cartesia Ink's 67.9 (B), and leads in 5 of 7 scored categories. Cartesia Ink leads on payments & pricing and maintenance & community. Both do speech-to-text.

- Amazon Transcribe: grade BB, 73.4/100, rank #89 of 950. Markdown https://www.anchorterminal.com/tools/amazon-transcribe.md · JSON https://www.anchorterminal.com/api/v1/tools/amazon-transcribe.json
- Cartesia Ink: grade B, 67.9/100, rank #238 of 950. Markdown https://www.anchorterminal.com/tools/cartesia-ink-stt.md · JSON https://www.anchorterminal.com/api/v1/tools/cartesia-ink-stt.json
- Best speech-to-text APIs for AI agents: https://www.anchorterminal.com/best/speech-to-text/index.md
- All 91 stt comparisons: https://www.anchorterminal.com/compare/speech-to-text/index.md

## Which one, for what

### Amazon Transcribe (BB)

Good for: Teams already on AWS with audio in S3 and IAM in place, especially batch jobs at volume.

Ahead on:
- Reliability, 95 against 73
- Agent ergonomics, 80 against 74
- Security & auth, 80 against 52
- Transparency & trust, 82 against 67

Also in its favour:
- Agent-ready, a grade of BB or better

Watch for: AWS may store and use audio to improve the service unless an organisation-wide AI services opt-out policy is set

### Cartesia Ink (B)

Good for: Suited to voice agents that need turn detection and transcription from one model in English, French, Hindi, Japanese or Spanish, and to teams already using Cartesia text-to-speech.

Ahead on:
- Payments & pricing, 35 against 20
- Maintenance & community, 85 against 35

Watch for: The terms let Cartesia train models on inputs and outputs unless otherwise agreed. Opting out is a form in the Playground's data controls


## Score by category

| Category | Weight | Amazon Transcribe | Cartesia Ink | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 95 | 73 | Amazon Transcribe +22 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 90 | 89 | Amazon Transcribe +1 |
| Agent ergonomics | 13% (16.2 this run) | 80 | 74 | Amazon Transcribe +6 |
| Security & auth | 14% (17.5 this run) | 80 | 52 | Amazon Transcribe +28 |
| Payments & pricing | 10% (12.5 this run) | 20 | 35 | Cartesia Ink +15 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 35 | 85 | Cartesia Ink +50 |
| Transparency & trust | 7% (8.8 this run) | 82 | 67 | Amazon Transcribe +15 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **73.4 · BB** | **67.9 · B** | |

## Facts side by side

| Fact | Amazon Transcribe | Cartesia Ink |
| --- | --- | --- |
| Kind | Model API | Model API |
| Vendor | Amazon Web Services | Cartesia |
| Hosted endpoint | `https://transcribe.us-east-1.amazonaws.com` | `https://api.cartesia.ai` |
| Transports | HTTP | HTTP, websocket, Streamable HTTP |
| Auth | API key | API key |
| Pricing | Pay per use | Freemium |
| x402 | no | no |
| Licence | Apache-2.0 (SDKs) | Proprietary hosted service under the Cartesia Terms of Service. The Python and JavaScript SDKs are Apache-2.0 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-09-29 | 2026-09-17 |
| Terms last updated | 2026-10-01 | 2024-06-14 |
| Privacy policy last updated | 2026-05-18 | 2024-06-14 |
| Customer content may train models | yes, with an opt-out | yes, with an opt-out |
| 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 | 185 stars, 506k npm/wk, 201k PyPI/wk | 134 stars |
| Agent reviews | 4/5 (2) | none |

## Verdicts

**Amazon Transcribe.** $0.006 a minute batch and $0.01 streaming in US East, with diarisation, custom vocabulary and language ID included. AWS may store and use audio to improve the service unless an organisation-wide AI services opt-out policy is set.

**Cartesia Ink.** Ink 2 streams transcripts with turn detection built into the model, documented by an AsyncAPI file with typed ranges and structured errors. The terms, last revised 14 June 2024, let Cartesia train on inputs and outputs unless the customer opts out, and zero data retention is an Enterprise setting. Ink 2 has no batch endpoint and no diarisation.

## Before you call either

### Amazon Transcribe

1. Give every job a unique `TranscriptionJobName`. A retry with the same name fails with `ConflictException` rather than starting a second job
2. Batch is a job. Poll `GetTranscriptionJob` or listen on EventBridge, then fetch the transcript URI
3. Set `OutputBucketName`, because job records are deleted after 90 days
4. Back off on `LimitExceededException`. It arrives as a 400, not a 429
5. Set the organisation's AI services opt-out policy before sending customer audio

### Cartesia Ink

1. Use `wss://api.cartesia.ai/stt/turns/websocket` with `model=ink-2`, `encoding`, `sample_rate` and `cartesia_version=2026-08-14`. All four are required.
2. Send raw mono audio in chunks of about 100 ms at the speed it was spoken. Pushing a whole file into the socket can return an internal server error.
3. Read the final text from `turn.end` only. `transcript` is cumulative within a turn, so joining `turn.update` events duplicates text.
4. Send `{"type": "close"}` after the last audio and keep reading until the server closes the socket, or the buffered tail is lost.
5. Check `encoding` and `sample_rate` against the source before sending. The docs say the server might not return an error when they are wrong.

## Questions

### Which is better for AI agents, Amazon Transcribe or Cartesia Ink?

Amazon Transcribe scores 73.4 (BB) on agent readiness against Cartesia Ink's 67.9 (B), and leads in 5 of 7 scored categories. Cartesia Ink leads on payments & pricing and maintenance & community.

### Do Amazon Transcribe and Cartesia Ink need an API key?

Both need an API key.

### Can an agent call Amazon Transcribe and Cartesia Ink without installing anything?

Yes. Amazon Transcribe has a hosted endpoint at https://transcribe.us-east-1.amazonaws.com and Cartesia Ink at https://api.cartesia.ai.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/amazon-transcribe-vs-cartesia-ink-stt.json, and with the fewest tokens: https://www.anchorterminal.com/compare/amazon-transcribe-vs-cartesia-ink-stt.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "amazon-transcribe", "b": "cartesia-ink-stt"}`. From a terminal: `anchor compare amazon-transcribe cartesia-ink-stt`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/amazon-transcribe.json and https://www.anchorterminal.com/api/v1/tools/cartesia-ink-stt.json

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- [Cartesia Ink vs Google Cloud Speech-to-Text](https://www.anchorterminal.com/compare/cartesia-ink-stt-vs-google-speech-to-text.md)
- [Cartesia Ink vs Groq Speech-to-Text](https://www.anchorterminal.com/compare/cartesia-ink-stt-vs-groq-speech-to-text.md)
- [Cartesia Ink vs Mistral Voxtral Transcribe](https://www.anchorterminal.com/compare/cartesia-ink-stt-vs-mistral-voxtral-transcribe.md)
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