Documentation

Translation API

A simple REST API for translation. Send text, get a translation back — with automatic source-language detection and access to both LibreTranslate and DeepL engines depending on your plan.

Sign in and create a key from the dashboard. The Developer plan is free and needs no card. Endpoints and schemas below are stable for v1.

Base URL

https://api.lingua-api.com/v1

Authentication

Every request is authenticated with an API key sent as a Bearer token. Keys are scoped to your account, can be revoked at any time from the dashboard, and never expire on their own. Only a hash of the key is stored — copy it when it is shown.

Authorization: Bearer lk_live_xxxxxxxxxxxxxxxx

Keep keys server-side. Never ship them in browser or mobile code — proxy through your backend instead.

Quick start

Translate a string with automatic source detection. Every response includes a confidencefactor (0–1) for the detected source language, so you can route low-confidence detections to a human or retry with a pinned source.

curl -X POST https://api.lingua-api.com/v1/translate \
  -H "Authorization: Bearer $LINGUA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "text": "Hello world", "target": "ja" }'

# { "text": "こんにちは世界", "detected": "en", "confidence": 0.92,
#   "engine": "libre", "characters": 11 }