---
createdAt: 2025-04-18
updatedAt: 2026-05-06
title: Vite + Preact i18n - How to translate an Preact app in 2026
description: Discover how to make your Vite and Preact website multilingual. Follow the documentation to internationalize (i18n) and translate it.
keywords:
  - Internationalization
  - Documentation
  - Intlayer
  - Vite
  - Preact
  - JavaScript
slugs:
  - doc
  - environment
  - vite-and-preact
applicationTemplate: https://github.com/aymericzip/intlayer-vite-preact-template
applicationShowcase: https://intlayer-vite-preact-template.vercel.app
history:
  - version: 8.9.0
    date: 2026-05-04
    changes: "Update Solid useIntlayer API usage to direct property access"
  - version: 7.5.9
    date: 2025-12-30
    changes: "Add init command"
  - version: 7.0.0
    date: 2025-10-28
    changes: "Update LocaleRouter component to use new route configuration"
  - version: 5.5.10
    date: 2025-06-29
    changes: "Initial history"
---

# Translate your Vite and Preact website using Intlayer | Internationalization (i18n)

<Tabs defaultTab="video">
  <Tab label="Video" value="video">
  
<iframe title="The best i18n solution for Vite and Preact? Discover Intlayer" class="m-auto aspect-16/9 w-full overflow-hidden rounded-lg border-0" allow="autoplay; gyroscope;" loading="lazy" width="1080" height="auto" src="https://www.youtube.com/embed/dS9L7uJeak4?si=VaKmrYMmXjo3xpk2"/>

  </Tab>
  <Tab label="Code" value="code">

<iframe
  src="https://ide.intlayer.org/aymericzip/intlayer-vite-preact-template?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"
/>

  </Tab>
  <Tab label="Demo" value="demo">

<iframe
  src="https://intlayer-vite-preact-template.vercel.app"
  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 - intlayer-vite-preact-template"
  sandbox="allow-forms allow-modals allow-popups allow-presentation allow-same-origin allow-scripts"
  loading="lazy"
/>

  </Tab>
</Tabs>

## Table of Contents

<TOC/>

## What is Intlayer?

**Intlayer** is an innovative, open-source internationalization (i18n) library designed to simplify multilingual support in modern web applications.

With Intlayer, you can:

- **Easily manage translations** using declarative dictionaries at the component level.
- **Dynamically localize metadata**, routes, and content.
- **Ensure TypeScript support** with autogenerated types, improving autocompletion and error detection.
- **Benefit from advanced features**, like dynamic locale detection and switching.

---

## Step-by-Step Guide to Set Up Intlayer in a Vite and Preact Application

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

### Step 1: Install Dependencies

Install the necessary packages using npm:

```bash packageManager="npm"
npm install intlayer preact-intlayer
npm install vite-intlayer --save-dev
npx intlayer init
```

```bash packageManager="pnpm"
pnpm add intlayer preact-intlayer
pnpm add vite-intlayer --save-dev
pnpm intlayer init
```

```bash packageManager="yarn"
yarn add intlayer preact-intlayer
yarn add vite-intlayer --save-dev
yarn intlayer init
```

```bash packageManager="bun"
bun add intlayer preact-intlayer
bun add vite-intlayer --dev
bun x intlayer init
```

- **intlayer**

  The core package that provides internationalization tools for configuration management, translation, [content declaration](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/dictionary/content_file.md), transpilation, and [CLI commands](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/cli/index.md).

- **preact-intlayer**
  The package that integrates Intlayer with Preact application. It provides context providers and hooks for Preact internationalization.

- **vite-intlayer**
  Includes the Vite plugin for integrating Intlayer with the [Vite bundler](https://vite.dev/guide/why.html#why-bundle-for-production), as well as middleware for detecting the user's preferred locale, managing cookies, and handling URL redirection.

### Step 2: Configuration of your project

Create a config file to configure the languages of your application:

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

const config: IntlayerConfig = {
  internationalization: {
    locales: [
      Locales.ENGLISH,
      Locales.FRENCH,
      Locales.SPANISH,
      // Your other locales
    ],
    defaultLocale: Locales.ENGLISH,
  },
  routing: {
    mode: "prefix-no-default", // Default: prefix all locales except the default locale
    storage: ["cookie", "header"], // Default: store locale in cookie and detect from header
  },
};

export default config;
```

> Through this configuration file, you can set up localized URLs, routing modes, storage options, cookie names, the location and extension of your content declarations, disable Intlayer logs in the console, and more. For a complete list of available parameters, refer to the [configuration documentation](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/configuration.md).

### Step 3: Integrate Intlayer in Your Vite Configuration

Add the intlayer plugin into your configuration.

```typescript fileName="vite.config.ts" codeFormat={["typescript", "esm", "commonjs"]}
import { defineConfig } from "vite";
import preact from "@preact/preset-vite";
import { intlayer } from "vite-intlayer";

// https://vitejs.dev/config/
export default defineConfig({
  plugins: [preact(), intlayer()],
});
```

> The `intlayer()` Vite plugin is used to integrate Intlayer with Vite. It ensures the building of content declaration files and monitors them in development mode. It defines Intlayer environment variables within the Vite application. Additionally, it provides aliases to optimize performance.

### Step 4: Declare Your Content

Create and manage your content declarations to store translations:

```tsx fileName="src/app.content.tsx" contentDeclarationFormat={["typescript", "esm", "commonjs"]}
import { t, type Dictionary } from "intlayer";
import type { ComponentChildren } from "preact";

const appContent = {
  key: "app",
  content: {
    viteLogo: t({
      en: "Vite logo",
      fr: "Logo Vite",
      es: "Logo Vite",
    }),
    preactLogo: t({
      en: "Preact logo",
      fr: "Logo Preact",
      es: "Logo Preact",
    }),

    title: "Vite + Preact",

    count: t({
      en: "count is ",
      fr: "le compte est ",
      es: "el recuento es ",
    }),

    edit: t<ComponentChildren>({
      en: (
        <>
          Edit <code>src/app.tsx</code> and save to test HMR
        </>
      ),
      fr: (
        <>
          Éditez <code>src/app.tsx</code> et enregistrez pour tester HMR
        </>
      ),
      es: (
        <>
          Edita <code>src/app.tsx</code> y guarda para probar HMR
        </>
      ),
    }),

    readTheDocs: t({
      en: "Click on the Vite and Preact logos to learn more",
      fr: "Cliquez sur les logos Vite et Preact pour en savoir plus",
      es: "Haga clic en los logotipos de Vite y Preact para obtener más información",
    }),
  },
} satisfies Dictionary;

export default appContent;
```

```json fileName="src/app.content.json" contentDeclarationFormat="json"
{
  "$schema": "https://intlayer.org/schema.json",
  "key": "app",
  "content": {
    "viteLogo": {
      "nodeType": "translation",
      "translation": {
        "en": "Vite logo",
        "fr": "Logo Vite",
        "es": "Logo Vite"
      }
    },
    "preactLogo": {
      "nodeType": "translation",
      "translation": {
        "en": "Preact logo",
        "fr": "Logo Preact",
        "es": "Logo Preact"
      }
    },
    "title": {
      "nodeType": "translation",
      "translation": {
        "en": "Vite + Preact",
        "fr": "Vite + Preact",
        "es": "Vite + Preact"
      }
    },
    "count": {
      "nodeType": "translation",
      "translation": {
        "en": "count is ",
        "fr": "le compte est ",
        "es": "el recuento es "
      }
    },
    "edit": {
      "nodeType": "translation",
      "translation": {
        "en": "Edit src/app.tsx and save to test HMR",
        "fr": "Éditez src/app.tsx et enregistrez pour tester HMR",
        "es": "Edita src/app.tsx y guarda para probar HMR"
      }
    },
    "readTheDocs": {
      "nodeType": "translation",
      "translation": {
        "en": "Click on the Vite and Preact logos to learn more",
        "fr": "Cliquez sur les logos Vite et Preact pour en savoir plus",
        "es": "Haga clic en los logotipos de Vite y Preact para obtener más información"
      }
    }
  }
}
```

> Your content declarations can be defined anywhere in your application as soon they are included into the `contentDir` directory (by default, `./src`). And match the content declaration file extension (by default, `.content.{json,ts,tsx,js,jsx,mjs,cjs}`).

> For more details, refer to the [content declaration documentation](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/dictionary/content_file.md).

> If your content file includes TSX code, you might need to import `import { h } from "preact";` or ensure your JSX pragma is correctly set for Preact.

### Step 5: Utilize Intlayer in Your Code

Access your content dictionaries throughout your application:

```tsx {6,10} fileName="src/app.tsx" codeFormat={["typescript", "esm"]}
import { useState } from "preact/hooks";
import type { FunctionalComponent } from "preact";
import preactLogo from "./assets/preact.svg"; // Assuming you have a preact.svg
import viteLogo from "/vite.svg";
import "./app.css"; // Assuming your CSS file is named app.css
import { IntlayerProvider, useIntlayer } from "preact-intlayer";

const AppContent: FunctionalComponent = () => {
  const [count, setCount] = useState(0);
  const content = useIntlayer("app");

  return (
    <>
      <div>
        <a href="https://vitejs.dev" target="_blank">
          <img src={viteLogo} class="logo" alt={content.viteLogo.value} />
        </a>
        <a href="https://preactjs.com" target="_blank">
          <img
            src={preactLogo}
            class="logo preact"
            alt={content.preactLogo.value}
          />
        </a>
      </div>
      <h1>{content.title}</h1>
      <div class="card">
        <button onClick={() => setCount((count) => count + 1)}>
          {content.count}
          {count}
        </button>
        <p>{content.edit}</p>
      </div>
      {/* Markdown content */}
      <div>{content.myMarkdownContent}</div>

      {/* HTML content */}
      <div>{content.myHtmlContent}</div>

      <p class="read-the-docs">{content.readTheDocs}</p>
    </>
  );
};

const App: FunctionalComponent = () => (
  <IntlayerProvider>
    <AppContent />
  </IntlayerProvider>
);

export default App;
```

> If you want to use your content in a `string` attribute, such as `alt`, `title`, `href`, `aria-label`, etc., you can use the value of the function, like:

> ```html
> <img src="{content.image.src.value}" alt="{content.image.value}" />
> <img src="{content.image.src.toString()}" alt="{content.image.toString()}" />
> <img src="{String(content.image.src)}" alt="{String(content.image)}" />
> ```

> Note: In Preact, `className` is typically written as `class`.

> To Learn more about the `useIntlayer` hook, refer to the [documentation](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/packages/react-intlayer/useIntlayer.md) (The API is similar for `preact-intlayer`).

> If your app already exists, you can use the [Intlayer Compiler](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/compiler.md), as well as the [extract command](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/cli/extract.md), to transform thousands of components in a second.

### (Optional) Step 6: Change the language of your content

To change the language of your content, you can use the `setLocale` function provided by the `useLocale` hook. This function allows you to set the locale of the application and update the content accordingly.

```tsx fileName="src/components/LocaleSwitcher.tsx" codeFormat={["typescript", "esm"]}
import type { FunctionalComponent } from "preact";
import { Locales } from "intlayer";
import { useLocale } from "preact-intlayer";

const LocaleSwitcher: FunctionalComponent = () => {
  const { setLocale } = useLocale();

  return (
    <button onClick={() => setLocale(Locales.ENGLISH)}>
      Change Language to English
    </button>
  );
};

export default LocaleSwitcher;
```

> To Learn more about the `useLocale` hook, refer to the [documentation](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/packages/react-intlayer/useLocale.md) (The API is similar for `preact-intlayer`).

### (Optional) Step 7: Add localized Routing to your application

The purpose of this step is to make unique routes for each language. This is useful for SEO and SEO-friendly URLs.
Example:

```plaintext
- https://example.com/about
- https://example.com/es/about
- https://example.com/fr/about
```

> By default, the routes are not prefixed for the default locale. If you want to prefix the default locale, you can set the `routing.mode` option to `"prefix-all"` in your configuration. See the [configuration documentation](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/configuration.md) for more information.

To add localized routing to your application, you can create a `LocaleRouter` component that wraps your application's routes and handles locale-based routing. Here is an example using [preact-iso](https://github.com/preactjs/preact-iso):

```tsx fileName="src/components/LocaleRouter.tsx" codeFormat={["typescript", "esm"]}
import { localeMap } from "intlayer";
import { IntlayerProvider } from "preact-intlayer";
import { LocationProvider, Router, Route } from "preact-iso";
import type { ComponentChildren, FunctionalComponent } from "preact";

/**
 * A router component that sets up locale-specific routes.
 * It uses preact-iso to manage navigation and render localized components.
 */
export const LocaleRouter: FunctionalComponent<{
  children: ComponentChildren;
}> = ({ children }) => (
  <LocationProvider>
    <Router>
      {localeMap(({ locale, urlPrefix }) => ({ locale, urlPrefix }))
        .sort((a, b) => b.urlPrefix.length - a.urlPrefix.length)
        .map(({ locale, urlPrefix }) => (
          <Route
            key={locale}
            path={`${urlPrefix}/:rest*`}
            component={() => (
              <IntlayerProvider locale={locale}>{children}</IntlayerProvider>
            )}
          />
        ))}
    </Router>
  </LocationProvider>
);
```

Then, you can use the `LocaleRouter` component in your application:

```tsx fileName="src/app.tsx" codeFormat={["typescript", "esm"]}
import { LocaleRouter } from "./components/LocaleRouter";
import type { FunctionalComponent } from "preact";

// ... Your AppContent component

const App: FunctionalComponent = () => (
  <LocaleRouter>
    <AppContent />
  </LocaleRouter>
);

export default App;
```

In parallel, you can also use the `intlayerProxy` to add server-side routing to your application. This plugin will automatically detect the current locale based on the URL and set the appropriate locale cookie. If no locale is specified, the plugin will determine the most appropriate locale based on the user's browser language preferences. If no locale is detected, it will redirect to the default locale.

> Note that to use the `intlayerProxy` in production, you need to switch the `vite-intlayer` package from `devDependencies` to `dependencies`.

```typescript {3,7} fileName="vite.config.ts"
import { defineConfig } from "vite";
import { intlayer, intlayerProxy } from "vite-intlayer";
import preact from "@preact/preset-vite";

// https://vitejs.dev/config/
export default defineConfig({
  plugins: [
    intlayerProxy(), // should be placed first
    preact(),
    intlayer(),
  ],
});
```

### (Optional) Step 8: Change the URL when the locale changes

To change the URL when the locale changes, you can use the `onLocaleChange` prop provided by the `useLocale` hook. In parallel, you can use the `route` method from `useLocation` of `preact-iso` to update the URL path.

```tsx fileName="src/components/LocaleSwitcher.tsx" codeFormat={["typescript", "esm"]}
import { useLocation } from "preact-iso";
import {
  Locales,
  getHTMLTextDir,
  getLocaleName,
  getLocalizedUrl,
} from "intlayer";
import { useLocale } from "preact-intlayer";
import type { FunctionalComponent } from "preact";

const LocaleSwitcher: FunctionalComponent = () => {
  const { url, route } = useLocation();
  const { locale, availableLocales, setLocale } = useLocale({
    onLocaleChange: (newLocale) => {
      // Construct the URL with the updated locale
      // Example: /es/about?foo=bar
      const pathWithLocale = getLocalizedUrl(url, newLocale);

      // Update the URL path
      route(pathWithLocale, true); // true for replace
    },
  });

  return (
    <div>
      <button popovertarget="localePopover">{getLocaleName(locale)}</button>
      <div id="localePopover" popover="auto">
        {availableLocales.map((localeItem) => (
          <a
            href={getLocalizedUrl(url, localeItem)}
            hreflang={localeItem}
            aria-current={locale === localeItem ? "page" : undefined}
            onClick={(e) => {
              e.preventDefault();
              setLocale(localeItem);
              // Programmatic navigation after setting locale will be handled by onLocaleChange
            }}
            key={localeItem}
          >
            <span>
              {/* Locale - e.g. FR */}
              {localeItem}
            </span>
            <span>
              {/* Language in its own Locale - e.g. Français */}
              {getLocaleName(localeItem, localeItem)}
            </span>
            <span dir={getHTMLTextDir(localeItem)} lang={localeItem}>
              {/* Language in current Locale - e.g. Francés with current locale set to Locales.SPANISH */}
              {getLocaleName(localeItem, locale)}
            </span>
            <span dir="ltr" lang={Locales.ENGLISH}>
              {/* Language in English - e.g. French */}
              {getLocaleName(localeItem, Locales.ENGLISH)}
            </span>
          </a>
        ))}
      </div>
    </div>
  );
};

export default LocaleSwitcher;
```

> Documentation references:
>
> > - [`useLocale` hook](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/packages/react-intlayer/useLocale.md) (API is similar for `preact-intlayer`)> - [`getLocaleName` hook](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/packages/intlayer/getLocaleName.md)> - [`getLocalizedUrl` hook](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/packages/intlayer/getLocalizedUrl.md)> - [`getHTMLTextDir` hook](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/packages/intlayer/getHTMLTextDir.md)> - [`hreflang` attribute](https://developers.google.com/search/docs/specialty/international/localized-versions?hl=fr)> - [`lang` attribute](https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/lang)> - [`dir` attribute](https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/dir)> - [`aria-current` attribute](https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/Attributes/aria-current)> - [Popover API](https://developer.mozilla.org/en-US/docs/Web/API/Popover_API)

Below is the updated **Step 9** with added explanations and refined code examples:

---

### (Optional) Step 9: Switch the HTML Language and Direction Attributes

When your application supports multiple languages, it's crucial to update the `<html>` tag's `lang` and `dir` attributes to match the current locale. Doing so ensures:

- **Accessibility**: Screen readers and assistive technologies rely on the correct `lang` attribute to pronounce and interpret content accurately.
- **Text Rendering**: The `dir` (direction) attribute ensures that text is rendered in the proper order (e.g., left-to-right for English, right-to-left for Arabic or Hebrew), which is essential for readability.
- **SEO**: Search engines use the `lang` attribute to determine the language of your page, helping to serve the right localized content in search results.

By updating these attributes dynamically when the locale changes, you guarantee a consistent and accessible experience for users across all supported languages.

#### Implementing the Hook

Create a custom hook to manage the HTML attributes. The hook listens for locale changes and updates the attributes accordingly:

```tsx fileName="src/hooks/useI18nHTMLAttributes.tsx" codeFormat={["typescript", "esm"]}
import { useEffect } from "preact/hooks";
import { useLocale } from "preact-intlayer";
import { getHTMLTextDir } from "intlayer";

/**
 * Updates the HTML <html> element's `lang` and `dir` attributes based on the current locale.
 * - `lang`: Informs browsers and search engines of the page's language.
 * - `dir`: Ensures the correct reading order (e.g., 'ltr' for English, 'rtl' for Arabic).
 *
 * This dynamic update is essential for proper text rendering, accessibility, and SEO.
 */
export const useI18nHTMLAttributes = () => {
  const { locale } = useLocale();

  useEffect(() => {
    // Update the language attribute to the current locale.
    document.documentElement.lang = locale;

    // Set the text direction based on the current locale.
    document.documentElement.dir = getHTMLTextDir(locale);
  }, [locale]);
};
```

#### Using the Hook in Your Application

Integrate the hook into your main component so that the HTML attributes update whenever the locale changes:

```tsx fileName="src/app.tsx" codeFormat={["typescript", "esm"]}
import type { FunctionalComponent } from "preact";
import { IntlayerProvider } from "preact-intlayer"; // useIntlayer already imported if AppContent needs it
import { useI18nHTMLAttributes } from "./hooks/useI18nHTMLAttributes";
import "./app.css";
// AppContent definition from Step 5

const AppWithHooks: FunctionalComponent = () => {
  // Apply the hook to update the <html> tag's lang and dir attributes based on the locale.
  useI18nHTMLAttributes();

  // Assuming AppContent is your main content display component from Step 5
  return <AppContent />;
};

const App: FunctionalComponent = () => (
  <IntlayerProvider>
    <AppWithHooks />
  </IntlayerProvider>
);

export default App;
```

By applying these changes, your application will:

- Ensure the **language** (`lang`) attribute correctly reflects the current locale, which is important for SEO and browser behavior.
- Adjust the **text direction** (`dir`) according to the locale, enhancing readability and usability for languages with different reading orders.
- Provide a more **accessible** experience, as assistive technologies depend on these attributes to function optimally.

### (Optional) Step 10: Creating a Localized Link Component

To ensure that your application's navigation respects the current locale, you can create a custom `Link` component. This component automatically prefixes internal URLs with the current language.

This behavior is useful for several reasons:

- **SEO and User Experience**: Localized URLs help search engines index language-specific pages correctly and provide users with content in their preferred language.
- **Consistency**: By using a localized link throughout your application, you guarantee that navigation stays within the current locale, preventing unexpected language switches.
- **Maintainability**: Centralizing the localization logic in a single component simplifies the management of URLs.

Below is the implementation of a localized `Link` component in Preact:

```tsx fileName="src/components/Link.tsx" codeFormat={["typescript", "esm"]}
import { getLocalizedUrl } from "intlayer";
import { useLocale } from "preact-intlayer";
import { forwardRef } from "preact/compat";
import type { JSX } from "preact";

export interface LinkProps extends JSX.HTMLAttributes<HTMLAnchorElement> {
  href: string;
}

/**
 * Utility function to check whether a given URL is external.
 * If the URL starts with http:// or https://, it's considered external.
 */
export const checkIsExternalLink = (href?: string): boolean =>
  /^https?:\/\//.test(href ?? "");

/**
 * A custom Link component that adapts the href attribute based on the current locale.
 * For internal links, it uses `getLocalizedUrl` to prefix the URL with the locale (e.g., /fr/about).
 * This ensures that navigation stays within the same locale context.
 */
export const Link = forwardRef<HTMLAnchorElement, LinkProps>(
  ({ href, children, ...props }, ref) => {
    const { locale } = useLocale();
    const isExternalLink = checkIsExternalLink(href);

    // If the link is internal and a valid href is provided, get the localized URL.
    const hrefI18n =
      href && !isExternalLink ? getLocalizedUrl(href, locale) : href;

    return (
      <a href={hrefI18n} ref={ref} {...props}>
        {children}
      </a>
    );
  }
);

Link.displayName = "Link";
```

#### How It Works

- **Detecting External Links**:  
  The helper function `checkIsExternalLink` determines whether a URL is external. External links are left unchanged because they do not need localization.
- **Retrieving the Current Locale**:  
  The `useLocale` hook provides the current locale (e.g., `fr` for French).
- **Localizing the URL**:  
  For internal links (i.e., non-external), `getLocalizedUrl` is used to automatically prefix the URL with the current locale. This means that if your user is in French, passing `/about` as the `href` will transform it to `/fr/about`.
- **Returning the Link**:  
  The component returns an `<a>` element with the localized URL, ensuring that navigation is consistent with the locale.

### (Optional) Step 11: Render Markdown and HTML

Intlayer supports rendering Markdown and HTML content in Preact.

You can customize the rendering of Markdown and HTML content by using the `.use()` method. This method allows you to override the default rendering of specific tags.

```tsx
import { useIntlayer } from "preact-intlayer";

const { myMarkdownContent, myHtmlContent } = useIntlayer("my-component");

// ...

return (
  <div>
    {/* Basic rendering */}
    {myMarkdownContent}

    {/* Custom rendering for Markdown */}
    {myMarkdownContent.use({
      h1: (props) => <h1 style={{ color: "red" }} {...props} />,
    })}

    {/* Basic rendering for HTML */}
    {myHtmlContent}

    {/* Custom rendering for HTML */}
    {myHtmlContent.use({
      b: (props) => <strong style={{ color: "blue" }} {...props} />,
    })}
  </div>
);
```

### (Optional) Step 12: Extract the content of your components

If you have an existing codebase, transforming thousands of files can be time-consuming.

To ease this process, Intlayer propose a [compiler](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/compiler.md) / [extractor](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/cli/extract.md) to transform your components and extract the content.

To set it up, you can add a `compiler` section in your `intlayer.config.ts` file:

```typescript fileName="intlayer.config.ts" codeFormat={["typescript", "esm", "commonjs"]}
import { type IntlayerConfig } from "intlayer";

const config: IntlayerConfig = {
  // ... Rest of your config
  compiler: {
    /**
     * Indicates if the compiler should be enabled.
     */
    enabled: true,

    /**
     * Defines the output files path
     */
    output: ({ fileName, extension }) => `./${fileName}${extension}`,

    /**
     * Indicates if the components should be saved after being transformed.
     *
     * - If `true`, the compiler will rewrite the component file in the disk. So the transformation will be permanent, and the compiler will skip the transformation for the next process. That way, the compiler can transform the app, and then it can be removed.
     *
     * - If `false`, the compiler will inject the `useIntlayer()` function call into the code in the build output only, and keep the base codebase intact. The transformation will be done only in memory.
     */
    saveComponents: false,

    /**
     * Dictionary key prefix
     */
    dictionaryKeyPrefix: "",
  },
};

export default config;
```

<Tabs>
 <Tab value='Extract command'>

Run the extractor to transform your components and extract the content

```bash packageManager="npm"
npx intlayer extract
```

```bash packageManager="pnpm"
pnpm intlayer extract
```

```bash packageManager="yarn"
yarn intlayer extract
```

```bash packageManager="bun"
bun x intlayer extract
```

 </Tab>
 <Tab value='Babel compiler'>

Update your `vite.config.ts` to include the `intlayerCompiler` plugin:

```ts fileName="vite.config.ts"
import { defineConfig } from "vite";
import { intlayer, intlayerCompiler } from "vite-intlayer";

export default defineConfig({
  plugins: [
    intlayer(),
    intlayerCompiler(), // Adds the compiler plugin
  ],
});
```

```bash packageManager="npm"
npm run build # Or npm run dev
```

```bash packageManager="pnpm"
pnpm run build # Or pnpm run dev
```

```bash packageManager="yarn"
yarn build # Or yarn dev
```

```bash packageManager="bun"
bun run build # Or bun run dev
```

 </Tab>
</Tabs>

### (Optional) Sitemap and robots.txt (build-time)

Intlayer includes formatters such as `generateSitemap` and `getMultilingualUrls` that produce crawler-ready multilingual `sitemap.xml` and `robots.txt` output you can write into your project’s `public/` folder. In practice you run a small Node script **before** Vite (for example `predev` / `prebuild` npm hooks) so those files exist when you build or serve the app.

#### Sitemap

Intlayer’s sitemap generator respects your locale setup and includes the usual metadata for crawlers.

> The generated sitemap supports the `xhtml:link` namespace (hreflang XML extensions). Unlike basic generators that only emit flat URLs, Intlayer wires bidirectional links between every localized variant of each page (for example `/about`, `/fr/about`, or `/about?lang=fr`, depending on your routing mode), which helps search engines relate localized URLs.

#### Robots.txt

Use `getMultilingualUrls` so `Disallow` entries cover every localized spelling of sensitive paths.

#### 1. Add `generate-seo.mjs` at the project root

```javascript fileName="generate-seo.mjs"
import fs from "fs";
import path from "path";
import { fileURLToPath } from "url";
import { generateSitemap, getMultilingualUrls } from "intlayer";

const __dirname = path.dirname(fileURLToPath(import.meta.url));

const SITE_URL = (process.env.SITE_URL || "http://localhost:5173").replace(
  /\/$/,
  ""
);

const pathList = [
  { path: "/", changefreq: "daily", priority: 1.0 },
  { path: "/about", changefreq: "monthly", priority: 0.7 },
];

const sitemapXml = generateSitemap(pathList, { siteUrl: SITE_URL });
fs.writeFileSync(path.join(__dirname, "public", "sitemap.xml"), sitemapXml);

const getAllMultilingualUrls = (urls) =>
  urls.flatMap((url) => Object.values(getMultilingualUrls(url)));

const disallowedPaths = getAllMultilingualUrls(["/admin", "/private"]);

const robotsTxt = [
  "User-agent: *",
  "Allow: /",
  ...disallowedPaths.map((path) => `Disallow: ${path}`),
  "",
  `Sitemap: ${SITE_URL}/sitemap.xml`,
].join("\n");

fs.writeFileSync(path.join(__dirname, "public", "robots.txt"), robotsTxt);

console.log("SEO files generated successfully.");
```

`intlayer` must be installed so the script can import it. Set `SITE_URL` in the environment for production (for example in CI).

> Prefer `generate-seo.mjs` for Node ESM. If you use `generate-seo.js` instead, ensure `"type": "module"` is set in `package.json`, or run Node with ESM enabled.

#### 2. Run the script before Vite

```json fileName="package.json"
{
  "scripts": {
    "dev": "vite",
    "prebuild": "node generate-seo.mjs",
    "build": "vite build",
    "preview": "vite preview"
  }
}
```

Adjust if you use pnpm or yarn. You can also invoke the same script from CI or another step if that fits your workflow.

### Configure TypeScript

Intlayer use module augmentation to get benefits of TypeScript and make your codebase stronger.

![Autocompletion](https://github.com/aymericzip/intlayer/blob/main/docs/assets/autocompletion.png?raw=true)

![Translation error](https://github.com/aymericzip/intlayer/blob/main/docs/assets/translation_error.png?raw=true)

Ensure your TypeScript configuration includes the autogenerated types.

```json5 fileName="tsconfig.json"
{
  // ... Your existing TypeScript configurations
  "compilerOptions": {
    // ...
    "jsx": "react-jsx",
    "jsxImportSource": "preact", // Recommended for Preact 10+
    // ...
  },
  "include": [
    // ... Your existing TypeScript configurations
    ".intlayer/**/*.ts", // Include the auto-generated types
  ],
}
```

> Ensure your `tsconfig.json` is set up for Preact, especially `jsx` and `jsxImportSource` or `jsxFactory`/`jsxFragmentFactory` for older Preact versions if not using `preset-vite`'s defaults.

### Git Configuration

It is recommended to ignore the files generated by Intlayer. This allows you to avoid committing them to your Git repository.

To do this, you can add the following instructions to your `.gitignore` file:

```bash
# 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

To go further, you can implement the [visual editor](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_visual_editor.md) or externalize your content using the [CMS](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_CMS.md).

---
