REST API

A translation API that actually preserves your formatting.

One endpoint. Any format. 36 languages. Clean JSON in, translated JSON out — with every Markdown heading, JSON key, and HTML attribute exactly where you left it.

Integrate your CMS publish hook, i18n pipeline, or deployment workflow in minutes.

Get your free API key Read the docs →

Get your first translation in under 5 minutes.

curl -X POST https://api.usepolylingo.com/v1/translate \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "content": "# Hello World\n\nThis is **bold** text.",
    "format": "markdown",
    "targets": ["es", "fr", "de", "zh", "ar"],
    "model": "standard"
  }'

Every format, handled correctly

PolyLingo detects the format automatically or you can specify it explicitly. Structure is never touched — only the text inside it.

Markdown

Headings, bold, italic, links, code fences, lists — all preserved exactly. Only the text nodes are translated.

# Hello → # Hola

{}

JSON

Keys stay untouched. Only string values are translated. Nested objects and arrays are handled recursively.

"greeting": "Hello" → "greeting": "Hola"

HTML

Tags, attributes, class names, href values — never modified. Only visible text nodes are translated.

<h1>Hello</h1> → <h1>Hola</h1>

Plain text

Clean translation with no markup concerns. Auto-detected when no format markers are present.

"Hello World" → "Hola Mundo"

Rate limits by plan

Plan	Requests / min	Tokens / month
Free	10 req / min	100,000 / month
Starter	60 req / min	600,000 / month
GrowthPopular	200 req / min	2,500,000 / month
Scale	600 req / min	8,000,000 / month

All tiers use sliding-window rate limiting keyed to your API key. See full pricing →

36 languages supported

Full coverage including RTL languages — Arabic, Hebrew, Persian, and Urdu — with correct text direction handling in structured formats.

arArabic

RTL

zhChinese (Simplified)

nlDutch

enEnglish

fiFinnish

frFrench

deGerman

elGreek

heHebrew

RTL

hiHindi

huHungarian

idIndonesian

itItalian

jaJapanese

koKorean

msMalay

noNorwegian

faPersian

RTL

plPolish

ptPortuguese

roRomanian

ruRussian

esSpanish

svSwedish

tlTagalog

thThai

trTurkish

ukUkrainian

urUrdu

RTL

viVietnamese

Official SDKs

Use the typed Node.js or Python clients — same REST surface as the API reference, with helpers for async translation jobs.

npm

Node.js (npm)

TypeScript, ESM + CJS, Node 18+. npm install polylingo

Node SDK docs →PyPI

Python (PyPI)

httpx-based sync and async. pip install polylingo

Python SDK docs →

Start building for free

50,000 free tokens per month. No credit card. No commitment.

Get your API key