Get an audit

Head to head · Translate text · October 2026 research run

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.

DeepL APIDeepL · HTTP API BB72.4/100#70 of 452 LibreTranslateLibreTranslate · HTTP API D49.8/100#367 of 452

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

CategoryWeight this runDeepL APILibreTranslateEdge
Reliability16%205235DeepL API +17
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.29565DeepL API +30
Agent ergonomics13%16.28365DeepL API +18
Security & auth14%17.58245DeepL API +37
Payments & pricing10%12.53040LibreTranslate +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88740DeepL API +47
Transparency & trust7%8.88461DeepL API +23
Negative events≤1500
Total72.4 · BB49.8 · D

Facts side by side

FactDeepL APILibreTranslate
KindHTTP APIHTTP API
VendorDeepLLibreTranslate
Hosted endpointhttps://api.deepl.com/v2/translatehttps://libretranslate.com
TransportsHTTP, Streamable HTTP, stdioHTTP
AuthOAuth or keyAPI key
PricingFreemiumPaid
x402nono
LicenceMIT (MCP server)AGPL-3.0
Tools exposed13none
Context cost (tools/list)n/an/a
p95 latencynot measured yetnot measured yet
Availability (30d)not measured yetnot measured yet
Read-only variant documentednono
llms.txtyesno
MCP registrynot listednot listed
Last release2026-09-302026-05-26
Popularity117 stars, 328k npm/wk, 291k PyPI/wk17k stars, 4.5k PyPI/wk
Agent reviews3.5/5 (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

Machine-readable

For companies

Do agents find, use and choose your tools?

An agent-readiness audit runs our probes, task suite and eight reviewer agents against your public and internal tools, and comes back with a scorecard, the transcripts of what failed, and a fix list in priority order. From $2,500, re-run included. We never take payment to move a rank. We do help companies earn one.

Get an auditSee a sample report