What is LibreTranslate?

LibreTranslate is a free, open-source machine translation API that you can self-host on your own server. It supports over 30 languages and provides a REST API compatible with many applications, with no external API keys or rate limits required.

How many languages does LibreTranslate support?

LibreTranslate supports over 30 languages including English, Arabic, French, Spanish, German, Chinese, Russian, and many more. Language models are downloaded automatically on first use or can be pre-installed during setup.

Is LibreTranslate accurate?

LibreTranslate uses Argos Translate models which provide good accuracy for common language pairs. For production use cases requiring very high accuracy, consider combining it with post-editing workflows. It is ideal for bulk translation, development, and privacy-sensitive workloads where sending data to cloud APIs is not acceptable.

How do I protect my LibreTranslate API?

LibreTranslate supports API key authentication. You can enable it by setting the LT_API_KEYS environment variable and creating keys via the admin panel. Place a reverse proxy (Nginx Proxy Manager or Caddy) in front with HTTPS to secure traffic in transit.

🌍 Setup LibreTranslate — Self-Hosted Machine Translation API

Q: Can I use LibreTranslate without internet access?

Yes. Once the language models are downloaded and installed, LibreTranslate operates completely offline. This makes it suitable for air-gapped environments, internal enterprise networks, and privacy-sensitive deployments where data must not leave the organization.

Deploy a free, open-source translation API on your own server — no API keys, no rate limits, full privacy for your translation needs.

⚠️ This script is provided for demo and testing purposes only. Not intended for production use.

📦 Resources & Setup Scripts

Grab the automated bash script from GitHub to follow along with the video.

Quick Install:

wget https://raw.githubusercontent.com/mhmdali94/Docker/main/tools/libretranslate/libretranslate-ubuntu.sh
chmod +x libretranslate-ubuntu.sh
sudo bash libretranslate-ubuntu.sh

Tutorial Steps

1 Download & Run the Installer

The script installs Docker if not already present, pulls the LibreTranslate image, and starts the container with all required language models. The initial startup may take a few minutes while language packs are downloaded.

wget https://raw.githubusercontent.com/mhmdali94/Docker/main/tools/libretranslate/libretranslate-ubuntu.sh
chmod +x libretranslate-ubuntu.sh
sudo bash libretranslate-ubuntu.sh

2 Access the Web UI

Open your browser and navigate to the LibreTranslate web interface to test translations interactively:

http://<your-server-ip>:5000

3 Test the Translation API

Use the built-in interactive API explorer at the web UI, or send direct HTTP requests to test the translation endpoint. The API accepts JSON with the source text, source language, and target language.

curl -X POST http://<your-server-ip>:5000/translate \
  -H "Content-Type: application/json" \
  -d '{"q":"Hello","source":"en","target":"ar"}'

4 Integrate with Your Application

Call the REST API from any programming language by sending POST requests with the source and target language codes. Replace <your-server-ip> with your server's IP address in your application configuration. The API is compatible with many LibreTranslate client libraries available for Python, JavaScript, PHP, and more.

curl -X POST http://<your-server-ip>:5000/translate \
  -H "Content-Type: application/json" \
  -d '{"q":"Hello","source":"en","target":"ar"}'

Ports Used

Port	Purpose
5000	LibreTranslate API & Web UI

Overview

LibreTranslate is a free and open-source machine translation API powered by the Argos Translate engine. It supports translation between dozens of languages and provides a REST API compatible with applications, scripts, and browser extensions — all without sending data to Google or DeepL.

Why Use It

Self-hosting LibreTranslate eliminates per-character API fees from commercial providers and keeps translated content private. It is ideal for internal document translation workflows, adding translation to existing apps, or complying with data residency requirements.

When You Need It

Who Should Use It

Real Use Cases

Main Features

How to Use After Installation

Security Best Practices

Ports and Firewall Notes

LibreTranslate runs on port 5000. If used internally, keep this port firewalled from the public internet and access via VPN. For public-facing APIs, place it behind a reverse proxy with API key enforcement and rate limiting.

Backup and Maintenance

Common Mistakes

Troubleshooting

Alternatives

Alternatives include Google Translate API (cloud, per-character cost), DeepL API (higher quality, paid), Lingvanex (self-hostable, commercial), and Argos Translate (Python library only). Choose LibreTranslate for a REST API with a web UI and Docker deployment.

When Not to Use It

Avoid LibreTranslate if translation quality is critical — commercial engines like DeepL produce significantly better results especially for professional or published content. Also avoid on low-RAM servers as each language pair model requires substantial memory.

PrismaTechWork Professional Help

PrismaTechWork provides end-to-end infrastructure services — from initial deployment and security hardening to ongoing monitoring, automated backups, and dedicated support. Whether you need a single-server setup or a multi-site network, our team ensures your infrastructure is built right, secured properly, and maintained reliably.

Frequently Asked Questions

How good is LibreTranslate translation quality?

LibreTranslate uses the Argos Translate engine which provides decent quality for common language pairs like English-Spanish or English-French. Quality is lower than DeepL or Google Translate, especially for complex sentences or less common languages. It is best suited for internal, draft, or automated translation rather than published content.

How do I add more languages?

Languages are added by downloading Argos Translate model packages. In the LibreTranslate admin panel, go to Languages and install the language pairs you need. Each pair such as English-to-Arabic is a separate model file that must be downloaded, requiring internet access for initial setup.

Can I use LibreTranslate API in my app?

Yes. LibreTranslate provides a REST API. Send a POST request to /translate with a JSON body containing the source text, source language code, and target language code. The API returns the translated text. Full documentation is available at the /docs path on your instance.

Does LibreTranslate work offline?

Yes — once language models are downloaded during setup, LibreTranslate operates fully offline. No internet connection is required for translation. This makes it suitable for air-gapped environments after initial model installation.

How do I restrict who can use my LibreTranslate instance?

Enable API key authentication by setting the LT_API_KEYS=true environment variable. Then create API keys via the admin panel. All requests must include a valid api_key parameter. You can set per-key rate limits to prevent abuse.