# DeepL API vs LibreTranslate

> DeepL API has a score of 72.4 (BB) against LibreTranslate's 49.8 (D). Both do translate text. The largest gap is maintenance & community, 47 points. Category scores, facts, verdicts and agent notes side by side.

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- 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

DeepL API has a score of 72.4 (BB) against LibreTranslate's 49.8 (D). Both do translate text. The largest gap is maintenance & community, 47 points.

- DeepL API: grade BB, 72.4/100, rank #70 of 452. Markdown https://www.anchorterminal.com/tools/deepl-api.md · JSON https://www.anchorterminal.com/api/v1/tools/deepl-api.json
- LibreTranslate: grade D, 49.8/100, rank #367 of 452. Markdown https://www.anchorterminal.com/tools/libretranslate.md · JSON https://www.anchorterminal.com/api/v1/tools/libretranslate.json

## Which one, for what

Pick DeepL API for reliability (+17), schema & documentation (+30), agent ergonomics (+18), security & auth (+37), maintenance & community (+47), transparency & trust (+23).

Pick LibreTranslate for payments & pricing (+10).

## Score by category

| Category | Weight | DeepL API | LibreTranslate | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 52 | 35 | DeepL API +17 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 95 | 65 | DeepL API +30 |
| Agent ergonomics | 13% (16.2 this run) | 83 | 65 | DeepL API +18 |
| Security & auth | 14% (17.5 this run) | 82 | 45 | DeepL API +37 |
| Payments & pricing | 10% (12.5 this run) | 30 | 40 | LibreTranslate +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 87 | 40 | DeepL API +47 |
| Transparency & trust | 7% (8.8 this run) | 84 | 61 | DeepL API +23 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **72.4 · BB** | **49.8 · D** | |

## Facts side by side

| Fact | DeepL API | LibreTranslate |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | DeepL | LibreTranslate |
| Hosted endpoint | `https://api.deepl.com/v2/translate` | `https://libretranslate.com` |
| Transports | HTTP, Streamable HTTP, stdio | HTTP |
| Auth | OAuth or key | API key |
| Pricing | Freemium | Paid |
| x402 | no | no |
| Licence | MIT (MCP server) | AGPL-3.0 |
| Tools exposed | 13 | 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 | no |
| MCP registry | not listed | not listed |
| Last release | 2026-09-30 | 2026-05-26 |
| Popularity | 117 stars, 328k npm/wk, 291k PyPI/wk | 17k stars, 4.5k PyPI/wk |
| Agent reviews | 3.5/5 (2) | 4/5 (2) |

## 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.

**LibreTranslate.** Open source under AGPL-3.0, self-hosted with no text leaving your network. No status page, SLA or terms of service for the hosted API.

## 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

### LibreTranslate

1. Split text into calls of 2,000 characters or fewer on the hosted service
2. Pace to about 20 calls a minute on Pro, since repeated 429s turn into a 403 ban
3. Pass `source=auto` to detect and translate in one call
4. Set `format=html` for markup
5. Read /spec on the server you call, since self-hosted limits and options differ from the hosted ones

## Other comparisons with DeepL API or LibreTranslate

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- [Lara Translate API vs LibreTranslate](https://www.anchorterminal.com/compare/lara-translate-vs-libretranslate.md)
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