LibreTranslate — Self-Hosted Translation API with No Rate Limits

What it is

LibreTranslate is a self-hosted machine translation API powered by open-source Argos Translate models. It provides a REST API for text translation between supported languages with no API keys, no rate limits, and no data sent to third parties. LibreTranslate is a privacy-focused, drop-in replacement for Google Translate API.

LibreTranslate is for developers and organizations who need machine translation without sending text to cloud translation services, whether for privacy, compliance, or cost reasons.

The project is actively maintained with regular releases and a growing user community. Documentation covers common use cases, and the open-source nature means you can inspect the source code, contribute fixes, and adapt the tool to your specific requirements.

How it saves time or tokens

Google Translate API and DeepL charge per character with usage limits. LibreTranslate is free after the initial server setup. For applications that translate high volumes of text (documentation localization, chat translation, content migration), the cost savings are significant. Running locally also eliminates network latency for translation requests.

How to use

1. Deploy LibreTranslate via Docker.
2. The API is available on port 5000 by default.
3. Send POST requests to /translate with source text, source language, and target language.

Example

# Deploy via Docker
docker run -d --name libretranslate -p 5000:5000 libretranslate/libretranslate

# First run downloads language models (may take several minutes)

# Translate text
curl -X POST http://localhost:5000/translate \
  -H 'Content-Type: application/json' \
  -d '{"q": "Hello world", "source": "en", "target": "es"}'
# Response: {"translatedText": "Hola mundo"}

# List supported languages
curl http://localhost:5000/languages

Related on TokRepo

• AI Tools for Content -- Content translation and localization tools
• AI Tools for Self-Hosted -- Self-hosted application tools

Common pitfalls

• Language model downloads happen on first startup and can be several gigabytes. The container may appear unresponsive during this phase. Check logs with docker logs libretranslate.
• Translation quality varies by language pair. Common pairs (English-Spanish, English-French) are good. Rare pairs may produce lower quality. Test your specific language pair before relying on it.
• LibreTranslate defaults to allowing all origins for CORS. For production, restrict origins and consider adding API key authentication with the --api-keys flag.

Before adopting this tool, evaluate whether it fits your team's existing workflow. Read the official documentation thoroughly, and start with a small proof-of-concept rather than a full migration. Community forums, GitHub issues, and Stack Overflow are valuable resources when you encounter edge cases not covered in the documentation.