Intlayer

---
createdAt: 2025-03-09
updatedAt: 2025-12-30
title: Lynx and React i18n - How to translate your Lynx app – guide 2026
description: Discover how to make your Lynx and React mobile app multilingual. Follow the documentation to internationalize (i18n) and translate it.
keywords:
  - Internationalization
  - Documentation
  - Intlayer
  - Vite
  - React
  - Lynx
  - JavaScript
slugs:
  - doc
  - environment
  - lynx-and-react
applicationTemplate: https://github.com/aymericzip/intlayer-lynx-template
history:
  - version: 7.5.9
    date: 2025-12-30
    changes: Add init command
  - version: 5.5.10
    date: 2025-06-29
    changes: Init history
---

# Translate your Lynx and React mobile app website using Intlayer | Internationalization (i18n)

See [Application Template](https://github.com/aymericzip/intlayer-lynx-template) on GitHub.

<iframe
  src="https://stackblitz.com/github/aymericzip/intlayer-lynx-template?embed=1&ctl=1&file=intlayer.config.ts"
  className="m-auto overflow-hidden rounded-lg border-0 max-md:size-full max-md:h-[700px] md:aspect-16/9 md:w-full"
  title="Demo CodeSandbox - How to Internationalize your application using Intlayer"
  sandbox="allow-forms allow-modals allow-popups allow-presentation allow-same-origin allow-scripts"
  loading="lazy"
/>

## What is Intlayer?

**Intlayer** is an **innovative, open-source internationalization (i18n) library** that simplifies multilingual support in modern applications. It works in many JavaScript/TypeScript environments, **including Lynx** (via the `react-intlayer` package).

With Intlayer, you can:

- **Easily manage translations** using declarative dictionaries at the component level.
- **Ensure TypeScript support** with autogenerated types.
- **Dynamically localize** content, including **UI strings** (and in React for web, it can also localize HTML metadata, etc.).
- **Benefit from advanced features**, like dynamic locale detection and switching.

---

## Step 1: Install Dependencies

From your Lynx project, install the following packages:

```bash packageManager="npm"
npm install intlayer react-intlayer lynx-intlayer
npx intlayer init
```

```bash packageManager="pnpm"
pnpm add intlayer react-intlayer lynx-intlayer
pnpm intlayer init
```

```bash packageManager="yarn"
yarn add intlayer react-intlayer lynx-intlayer
yarn intlayer init
```

```bash packageManager="bun"
bun add intlayer react-intlayer lynx-intlayer
bunx intlayer init
```

### Packages

- **intlayer**  
  The core i18n toolkit for configuration, dictionary content, types generation, and CLI commands.

- **react-intlayer**  
  React integration that provides the context providers and React hooks you’ll use in Lynx for obtaining and switching locales.

- **lynx-intlayer**  
  Lynx integration that provides the plugin for integrating Intlayer with the Lynx bundler.

---

## Step 2: Create an Intlayer Config

In your project root (or anywhere convenient), create an **Intlayer config** file. It might look like this:

```ts fileName="intlayer.config.ts" codeFormat="typescript"
import { Locales, type IntlayerConfig } from "intlayer";

const config: IntlayerConfig = {
  internationalization: {
    locales: [
      Locales.ENGLISH,
      Locales.FRENCH,
      Locales.SPANISH,
      // ... Add any other locales you need
    ],
    defaultLocale: Locales.ENGLISH,
  },
};

export default config;
```

```js fileName="intlayer.config.mjs" codeFormat="esm"
import { Locales } from "intlayer";

/** @type {import('intlayer').IntlayerConfig} */
const config = {
  internationalization: {
    locales: [
      Locales.ENGLISH,
      Locales.FRENCH,
      Locales.SPANISH,
      // ... Add any other locales you need
    ],
    defaultLocale: Locales.ENGLISH,
  },
};

export default config;
```

```js fileName="intlayer.config.js" codeFormat="commonjs"
const { Locales } = require("intlayer");

/** @type {import('intlayer').IntlayerConfig} */
const config = {
  internationalization: {
    locales: [Locales.ENGLISH, Locales.FRENCH, Locales.SPANISH],
    defaultLocale: Locales.ENGLISH,
  },
};

module.exports = config;
```

Within this config, you can:

- Configure your **list of supported locales**.
- Set a **default** locale.
- Later, you may add more advanced options (e.g., logs, custom content directories, etc.).
- See the [Intlayer configuration docs](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/configuration.md) for more.

## Step 3: Add the Intlayer plugin to the Lynx bundler

To use Intlayer with Lynx, you need to add the plugin to your `lynx.config.ts` file:

```ts fileName="lynx.config.ts"
import { defineConfig } from "@lynx-js/rspeedy";
import { pluginIntlayerLynx } from "lynx-intlayer/plugin";

export default defineConfig({
  plugins: [
    // ... other plugins
    pluginIntlayerLynx(),
  ],
});
```

## Step 4: Add the Intlayer provider

To keep synchronized the user language across your application, you need to wrap your root component with the `IntlayerProvider` component from `react-intlayer`.

Also, you need to add the `intlayerPolyfill` function file to ensure that Intlayer can work properly.

```tsx fileName="src/index.tsx"
import { root } from "@lynx-js/react";

import { App } from "./App.js";
import { IntlayerProvider } from "react-intlayer";
import { intlayerPolyfill } from "lynx-intlayer";

intlayerPolyfill();

root.render(
  <IntlayerProvider>
    <App />
  </IntlayerProvider>
);

if (import.meta.webpackHot) {
  import.meta.webpackHot.accept();
}
```

## Step 5: Declare Your Content

Create **content declaration** files anywhere in your project (commonly within `src/`), using any of the extension formats that Intlayer supports:

- `.content.json`
- `.content.ts`
- `.content.tsx`
- `.content.js`
- `.content.jsx`
- `.content.mjs`
- `.content.mjx`
- `.content.cjs`
- `.content.cjx`
- etc.

Example:

```tsx fileName="src/app.content.ts" contentDeclarationFormat="typescript"
import { t, type Dictionary } from "intlayer";

const appContent = {
  key: "app",
  content: {
    title: "React",
    subtitle: t({
      en: "on Lynx",
      fr: "sur Lynx",
      es: "en Lynx",
    }),
    description: t({
      en: "Tap the logo and have fun!",
      fr: "Appuyez sur le logo et amusez-vous!",
      es: "¡Toca el logo y diviértete!",
    }),
    hint: [
      t({
        en: "Edit",
        fr: "Modifier",
        es: "Editar",
      }),
      " src/App.tsx ",
      t({
        en: "to see updates!",
        fr: "pour voir les mises à jour!",
        es: "para ver actualizaciones!",
      }),
    ],
  },
} satisfies Dictionary;

export default appContent;
```

```jsx fileName="src/app.content.mjx" contentDeclarationFormat="esm"
import { t } from "intlayer";

const appContent = {
  key: "app",
  content: {
    title: "React",
    subtitle: t({
      en: "on Lynx",
      fr: "sur Lynx",
      es: "en Lynx",
    }),
    description: t({
      en: "Tap the logo and have fun!",
      fr: "Appuyez sur le logo et amusez-vous!",
      es: "¡Toca el logo y diviértete!",
    }),
    hint: [
      t({
        en: "Edit",
        fr: "Modifier",
        es: "Editar",
      }),
      " src/App.tsx ",
      t({
        en: "to see updates!",
        fr: "pour voir les mises à jour!",
        es: "para ver actualizaciones!",
      }),
    ],
  },
};

export default appContent;
```

```jsx fileName="src/app.content.csx" contentDeclarationFormat="commonjs"
const { t } = require("intlayer");

/** @type {import('intlayer').Dictionary} */
const appContent = {
  key: "app",
  content: {
    title: "React",
    subtitle: t({
      en: "on Lynx",
      fr: "sur Lynx",
      es: "en Lynx",
    }),
    description: t({
      en: "Tap the logo and have fun!",
      fr: "Appuyez sur le logo et amusez-vous!",
      es: "¡Toca el logo y diviértete!",
    }),
    hint: [
      t({
        en: "Edit",
        fr: "Modifier",
        es: "Editar",
      }),
      " src/App.tsx ",
      t({
        en: "to see updates!",
        fr: "pour voir les mises à jour!",
        es: "para ver actualizaciones!",
      }),
    ],
  },
};

module.exports = appContent;
```

```json fileName="src/app.content.json" contentDeclarationFormat="json"
{
  "$schema": "https://intlayer.org/schema.json",
  "key": "app",
  "content": {
    "title": "React",
    "subtitle": {
      "nodeType": "translation",
      "translation": {
        "en": "on Lynx",
        "fr": "sur Lynx",
        "es": "en Lynx"
      }
    },
    "description": {
      "nodeType": "translation",
      "translation": {
        "en": "Tap the logo and have fun!",
        "fr": "Appuyez sur le logo et amusez-vous!",
        "es": "¡Toca el logo y diviértete!"
      }
    },
    "hint": [
      {
        "nodeType": "translation",
        "translation": {
          "en": "Edit",
          "fr": "Modifier",
          "es": "Editar"
        }
      },
      " src/App.tsx ",
      {
        "nodeType": "translation",
        "translation": {
          "en": "to see updates!",
          "fr": "pour voir les mises à jour!",
          "es": "para ver actualizaciones!"
        }
      }
    ]
  }
}
```

> For details on content declarations, see [Intlayer’s content docs](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/dictionary/content_file.md).

---

## Step 4: Use Intlayer in Your Components

Use the `useIntlayer` hook in child components to get localized content.

```tsx fileName="src/App.tsx"
import { useCallback, useState } from "@lynx-js/react";
import { useIntlayer } from "react-intlayer";

import "./App.css";
import arrow from "./assets/arrow.png";
import lynxLogo from "./assets/lynx-logo.png";
import reactLynxLogo from "./assets/react-logo.png";
import { LocaleSwitcher } from "./components/LocaleSwitcher.jsx";

export const App = () => {
  const [alterLogo, setAlterLogo] = useState(false);
  const { title, subtitle, description, hint } = useIntlayer("app");

  const onTap = useCallback(() => {
    "background only";
    setAlterLogo(!alterLogo);
  }, [alterLogo]);

  return (
    <view>
      <view className="Background" />
      <view className="App">
        <view className="Banner">
          <view className="Logo" bindtap={onTap}>
            {alterLogo ? (
              <image src={reactLynxLogo} className="Logo--react" />
            ) : (
              <image src={lynxLogo} className="Logo--lynx" />
            )}
          </view>
          <text className="Title">{title}</text>
          <text className="Subtitle">{subtitle}</text>
        </view>
        <view className="Content">
          <image src={arrow} className="Arrow" />
          <text className="Description">{description}</text>
          <text className="Hint">
            {hint[0]}
            <text style={{ fontStyle: "italic" }}>{hint[1]}</text>
            {hint[2]}
          </text>
        </view>
        <LocaleSwitcher />
        <view style={{ flex: 1 }}></view>
      </view>
    </view>
  );
};
```

> When using `content.someKey` in string-based props (e.g., a button’s `title` or a `Text` component’s `children`), **call `content.someKey.value`** to get the actual string.

---

## (Optional) Step 5: Change the App Locale

To switch locales from within your components, you can use the `useLocale` hook’s `setLocale` method:

```tsx fileName="src/components/LocaleSwitcher.tsx"
import { type FC } from "react";
import { getLocaleName } from "intlayer";
import { useLocale } from "react-intlayer";

export const LocaleSwitcher: FC = () => {
  const { setLocale, availableLocales, locale } = useLocale();

  return (
    <view
      style={{
        display: "flex",
        flexDirection: "row",
        justifyContent: "center",
        alignItems: "center",
        gap: 10,
      }}
    >
      {availableLocales.map((localeEl) => (
        <text
          key={localeEl}
          style={{
            color: localeEl === locale ? "#fff" : "#888",
            fontSize: "12px",
          }}
          bindtap={() => setLocale(localeEl)}
        >
          {getLocaleName(localeEl)}
        </text>
      ))}
    </view>
  );
};
```

This triggers a re-render of all components that use Intlayer content, now showing translations for the new locale.

> See [`useLocale` docs](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/packages/react-intlayer/useLocale.md) for more details.

## Configure TypeScript (if you use TypeScript)

Intlayer generates type definitions in a hidden folder (by default `.intlayer`) to improve autocompletion and catch translation errors:

```json5
// tsconfig.json
{
  // ... your existing TS config
  "include": [
    "src", // your source code
    ".intlayer/types/**/*.ts", // <-- ensure the auto-generated types are included
    // ... anything else you already include
  ],
}
```

This is what enables features like:

- **Autocompletion** for your dictionary keys.
- **Type checking** that warns if you access a non-existent key or mismatch the type.

---

## Git Configuration

To avoid committing auto-generated files by Intlayer, add the following to your `.gitignore`:

```plaintext
# Ignore the files generated by Intlayer
.intlayer
```

---

### VS Code Extension

To improve your development experience with Intlayer, you can install the official **Intlayer VS Code Extension**.

[Install from the VS Code Marketplace](https://marketplace.visualstudio.com/items?itemName=intlayer.intlayer-vs-code-extension)

This extension provides:

- **Autocompletion** for translation keys.
- **Real-time error detection** for missing translations.
- **Inline previews** of translated content.
- **Quick actions** to easily create and update translations.

For more details on how to use the extension, refer to the [Intlayer VS Code Extension documentation](https://intlayer.org/doc/vs-code-extension).

---

## Go Further

- **Visual Editor**: Use the [Intlayer Visual Editor](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_visual_editor.md) to manage translations visually.
- **CMS Integration**: You can also externalize and fetch your dictionary content from a [CMS](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_CMS.md).
- **CLI Commands**: Explore the [Intlayer CLI](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/cli/index.md) for tasks like **extracting translations** or **checking missing keys**.

---