Paraglide JS

Tool

Incremental Migration

Paraglide JS compiles any translation file format via inlang plugins. This means you can run Paraglide alongside your existing i18n library—both reading from the same translation files.

Why adopt Paraglide JS?

Type safety — Autocomplete for message keys and parameters, compile-time errors for typos
Smaller bundles — Tree-shaking removes unused translations, up to 70% smaller i18n bundle sizes
Better DX — Your IDE knows every message key and its parameters

How it works

No translation file migration — Paraglide reads your existing i18next, react-intl, or custom JSON files directly
Run both libraries in parallel — Use Paraglide in new code while existing code keeps working
Gradual adoption — Convert components at your own pace, or keep both forever
Same source of truth — Both libraries read from the same translation files

[!NOTE] This example uses i18next translation files, but the same approach works with any format that has an inlang plugin.

Setup

1. Install Paraglide JS

npx @inlang/paraglide-js@latest init

2. Add a plugin for your translation format

Paraglide uses inlang plugins to read translation files. Add the plugin that matches your existing format to project.inlang/settings.json:

{
  "baseLocale": "en",
  "locales": ["en", "de", "fr"],
  "modules": [
-    "https://cdn.jsdelivr.net/npm/@inlang/message-format-plugin@latest/dist/index.js"
+    "https://cdn.jsdelivr.net/npm/@inlang/plugin-i18next@latest/dist/index.js"
  ],
+  "plugin.inlang.i18next": {
+    "pathPattern": "./locales/{locale}.json"
+  }
}

Now Paraglide compiles your existing i18next translation files into typed message functions.

3. Use both libraries together

Both libraries read from the same translation files:

import i18next from 'i18next';
import { m } from './paraglide/messages.js';

// Same translation, two ways to access it
i18next.t('greeting', { name: 'World' });  // i18next (runtime)
m.greeting({ name: 'World' });              // Paraglide (compiled, typesafe)

Use Paraglide in new code. Existing i18next code keeps working unchanged.

Learn more about messages, parameters, and locale management →