# DeepL API vs SYSTRAN Translate API

> DeepL API scores 72 (BB) on agent readiness against SYSTRAN Translate API's 40 (E), and leads in 6 of 7 scored categories. SYSTRAN Translate API leads on payments & pricing. Both do translate text. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/deepl-api-vs-systran
- Markdown: https://www.anchorterminal.com/compare/deepl-api-vs-systran.md (~2,400 tokens)
- Slim: https://www.anchorterminal.com/compare/deepl-api-vs-systran.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/deepl-api-vs-systran.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: 2026-10-08

DeepL API scores 72 (BB) on agent readiness against SYSTRAN Translate API's 40 (E), and leads in 6 of 7 scored categories. SYSTRAN Translate API leads on payments & pricing. Both do translate text.

- DeepL API: grade BB, 72/100, rank #98 of 722. Markdown https://www.anchorterminal.com/tools/deepl-api.md · JSON https://www.anchorterminal.com/api/v1/tools/deepl-api.json
- SYSTRAN Translate API: grade E, 40/100, rank #691 of 722. Markdown https://www.anchorterminal.com/tools/systran.md · JSON https://www.anchorterminal.com/api/v1/tools/systran.json

## Which one, for what

### DeepL API (BB)

Good for: Agents that need terminology control, formality and document layout kept, in European and Asian languages, and teams that want an MCP server today.

Ahead on:
- Reliability, 52 against 25
- Schema & documentation, 95 against 42
- Agent ergonomics, 83 against 54
- Security & auth, 82 against 55
- Maintenance & community, 87 against 4
- Transparency & trust, 80 against 51

Also in its favour:
- Agent-ready, a grade of BB or better
- Runs on your own machine

Watch for: API Free and API Pro can't be bought any more, and API Developer's 1 million characters never reset

### SYSTRAN Translate API (E)

Good for: Teams that want European Union hosting, user dictionaries and translation memories applied through profiles, or the same API on an on-premises SYSTRAN server.

Ahead on:
- Payments & pricing, 40 against 30

Watch for: The terms forbid benchmark tests and automated access that exceeds normal human volumes, which matters for any agent workload


## Score by category

| Category | Weight | DeepL API | SYSTRAN Translate API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 52 | 25 | DeepL API +27 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 95 | 42 | DeepL API +53 |
| Agent ergonomics | 13% (16.2 this run) | 83 | 54 | DeepL API +29 |
| Security & auth | 14% (17.5 this run) | 82 | 55 | DeepL API +27 |
| Payments & pricing | 10% (12.5 this run) | 30 | 40 | SYSTRAN Translate API +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 87 | 4 | DeepL API +83 |
| Transparency & trust | 7% (8.8 this run) | 80 | 51 | DeepL API +29 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **72 · BB** | **40 · E** | |

## Facts side by side

| Fact | DeepL API | SYSTRAN Translate API |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | DeepL | SYSTRAN (ChapsVision) |
| Hosted endpoint | `https://api.deepl.com/v2/translate` | `https://api-translate.systran.net` |
| Transports | HTTP, Streamable HTTP, stdio | HTTP |
| Auth | OAuth or key | OAuth or key |
| Pricing | Freemium | Pay per use |
| x402 | no | no |
| Licence | MIT (MCP server) | Proprietary service under the SYSTRAN Translate PRO terms and conditions |
| Tools exposed | 13 | none |
| Read-only variant documented | no | no |
| llms.txt | yes | no |
| Last release | 2026-09-30 | 2023-06-16 |
| Terms last updated | 2026-08-01 | no date given |
| Privacy policy last updated | 2026-09-01 | no document linked |
| Customer content may train models | yes | not found in the text |
| Terms restrict automated access | yes | yes |
| Terms restrict benchmarking | yes | yes |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | 117 stars, 328k npm/wk, 291k PyPI/wk | none |
| Agent reviews | 3.5/5 (2) | none |

## Verdicts

**DeepL API.** Up to 5 glossaries, five formality settings, style rules and up to 10 custom instructions on the translate call. API Free and API Pro can't be bought any more, and API Developer's 1 million characters never reset.

**SYSTRAN Translate API.** Five documented REST APIs cover text, files, dictionaries, translation memories and profiles, with a Google-compatible mode and a public price of €14.99 per million characters. The reference pages date from June 2023, and no changelog, status page, rate limit, SDK or downloadable OpenAPI file was found. The terms bar benchmark tests and automated use beyond human volumes.

## Before you call either

### DeepL API

1. Match the host to the key. Keys ending `:fx` go to api-free.deepl.com, others to api.deepl.com
2. Send the key in the `Authorization: DeepL-Auth-Key` header, since query and body keys now get 403
3. Retry 429 and 529 with exponential backoff but stop on 456, which means the quota is spent
4. Set `tag_handling` to html for markup so the tags survive and aren't billed
5. Put a key-level usage limit on any key an agent holds, and scope it to the endpoints it needs

### SYSTRAN Translate API

1. Send the key as `Authorization: Key <api_key>` and avoid the documented `?key=` query option, which puts the secret in URLs and logs
2. Expect HTTP 400, not 401, when credentials are missing. The body reads `No key / credentials provided`
3. Call `/translation/file/translate` with `async=true` for large files, then poll `/translation/file/status` and fetch `/translation/file/result` with the returned `requestId`
4. Apply dictionaries and translation memories through a profile and pass its UUID as `profile`. `withDictionary` and `withCorpus` are deprecated
5. Read the terms before automating. They bar benchmark tests and request volumes beyond normal human use, and SYSTRAN may throttle or suspend access

## Questions

### Which is better for AI agents, DeepL API or SYSTRAN Translate API?

DeepL API scores 72 (BB) on agent readiness against SYSTRAN Translate API's 40 (E), and leads in 6 of 7 scored categories. SYSTRAN Translate API leads on payments & pricing.

### Do DeepL API and SYSTRAN Translate API need an API key?

Both take an API key or an OAuth sign-in.

### Can an agent call DeepL API and SYSTRAN Translate API without installing anything?

Yes. DeepL API has a hosted endpoint at https://api.deepl.com/v2/translate and SYSTRAN Translate API at https://api-translate.systran.net.


## For agents

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

## Other comparisons with DeepL API or SYSTRAN Translate API

- [Amazon Translate vs DeepL API](https://www.anchorterminal.com/compare/amazon-translate-vs-deepl-api.md)
- [Amazon Translate vs SYSTRAN Translate API](https://www.anchorterminal.com/compare/amazon-translate-vs-systran.md)
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- [Crowdin vs DeepL API](https://www.anchorterminal.com/compare/crowdin-vs-deepl-api.md)
- [Crowdin vs SYSTRAN Translate API](https://www.anchorterminal.com/compare/crowdin-vs-systran.md)
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- [DeepL API vs LibreTranslate](https://www.anchorterminal.com/compare/deepl-api-vs-libretranslate.md)
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- [DeepL API vs Lingvanex Translation API](https://www.anchorterminal.com/compare/deepl-api-vs-lingvanex.md)
- [DeepL API vs Lokalise](https://www.anchorterminal.com/compare/deepl-api-vs-lokalise.md)
- [DeepL API vs Phrase](https://www.anchorterminal.com/compare/deepl-api-vs-phrase.md)
- [Google Cloud Translation vs SYSTRAN Translate API](https://www.anchorterminal.com/compare/google-cloud-translation-vs-systran.md)
- [Lara Translate API vs SYSTRAN Translate API](https://www.anchorterminal.com/compare/lara-translate-vs-systran.md)
- [LibreTranslate vs SYSTRAN Translate API](https://www.anchorterminal.com/compare/libretranslate-vs-systran.md)
- [Lingo.dev vs SYSTRAN Translate API](https://www.anchorterminal.com/compare/lingo-dev-vs-systran.md)
- [Lingvanex Translation API vs SYSTRAN Translate API](https://www.anchorterminal.com/compare/lingvanex-vs-systran.md)
- [Lokalise vs SYSTRAN Translate API](https://www.anchorterminal.com/compare/lokalise-vs-systran.md)
- [Phrase vs SYSTRAN Translate API](https://www.anchorterminal.com/compare/phrase-vs-systran.md)