---
createdAt: 2024-03-07
updatedAt: 2026-05-06
title: Astro i18n Translation - How to translate an Astro application in 2026
description: Learn how to add internationalisation (i18n) to your Astro site with Intlayer. Follow this guide to make your site multilingual.
keywords:
  - internationalisation
  - documentation
  - Intlayer
  - Vite
  - React
  - i18n
  - JavaScript
slugs:
  - doc
  - environment
  - astro
applicationTemplate: https://github.com/aymericzip/intlayer-astro-template
applicationShowcase: https://intlayer-astro-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: "Added init command"
  - version: 6.2.0
    date: 2025-10-03
    changes: "Update of Astro integration, configuration and usage"
---

# Translate your Astro site with Intlayer | Internationalisation (i18n)

<Tabs defaultTab="code">
  <Tab label="Code" value="code">

<iframe
  src="https://ide.intlayer.org/aymericzip/intlayer-astro-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 internationalise your application with 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-astro-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-astro-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 internationalisation (i18n) library designed to simplify multilingual support in modern web applications.

With Intlayer, you can:

- **Manage translations easily**: Using declarative dictionaries at the component level.
- **Localise metadata, routes and content dynamically**.
- **Ensure TypeScript support**: With autogenerated types for better autocompletion and error detection.
- **Benefit from advanced features**: Such as dynamic language detection and switching.

---

## Step-by-Step Guide to Configure Intlayer in Astro

Check out the [application template](https://github.com/aymericzip/intlayer-astro-template) on GitHub.

### Step 1: Install Dependencies

Install the necessary packages using your preferred package manager:

```bash packageManager="npm"
npm install intlayer astro-intlayer
# Optional: If you add support for React islands
npm install react react-dom react-intlayer @astrojs/react
```

```bash packageManager="pnpm"
pnpm add intlayer astro-intlayer
# Optional: If you add support for React islands
pnpm add react react-dom react-intlayer @astrojs/react
```

```bash packageManager="yarn"
yarn add intlayer astro-intlayer
# Optional: If you add support for React islands
yarn add react react-dom react-intlayer @astrojs/react
```

- **intlayer**
  The core package that provides i18n tools for configuration management, translations, [content declaration](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en-GB/dictionary/content_file.md), transpilation, and [CLI commands](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en-GB/cli/index.md).

- **astro-intlayer**
  Includes the Astro integration plugin to link Intlayer with the [Vite bundler](https://vite.dev/guide/why.html#why-bundle-for-production), as well as the middleware to detect the user's preferred language, manage cookies, and handle URL redirects.

### Step 2: Configure Your Project

Create a configuration file to define your application's languages:

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

const config: IntlayerConfig = {
  internationalization: {
    locales: [
      Locales.ENGLISH,
      Locales.FRENCH,
      Locales.SPANISH,
      Locales.ENGLISH_UNITED_KINGDOM,
      // Your other languages
    ],
    defaultLocale: Locales.ENGLISH,
  },
};

export default config;
```

> Through this configuration file, you can configure localised URLs, middleware redirects, cookie names, location and extensions of content declarations, disable Intlayer logs in the console, and more. For a full list of available parameters, refer to the [configuration documentation](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en-GB/configuration.md).

### Step 3: Integrate Intlayer into Your Astro Configuration

Add the `intlayer` plugin to your Astro configuration.

```typescript fileName="astro.config.ts"
// @ts-check

import { intlayer } from "astro-intlayer";
import { defineConfig } from "astro/config";

// https://astro.build/config
export default defineConfig({
  integrations: [intlayer()],
});
```

> The `intlayer()` integration plugin is used to integrate Intlayer with Astro. It ensures the generation of the content declaration files and monitors them in development mode. It defines Intlayer environment variables within the Astro application and provides aliases to optimise performance.

### Step 4: Declare Your Content

Create and manage your content declarations to store translations:

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

const appContent = {
  key: "app",
  content: {
    title: t({
      en: "Hello World",
      fr: "Bonjour le monde",
      es: "Hola mundo",
      "en-GB": "Hello World",
    }),
  },
} satisfies Dictionary;

export default appContent;
```

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

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

### Step 5: Using Content in Astro

You can consume the dictionaries directly in your `.astro` files using the core helpers exported from `intlayer`.

```astro fileName="src/pages/index.astro"
---
import {
  getIntlayer,
  getLocaleFromPath,
  getLocalizedUrl,
  defaultLocale,
  localeMap,
  getHTMLTextDir,
  type LocalesValues,
} from "intlayer";
import LocaleSwitcher from "../components/LocaleSwitcher.astro";

// Get the current locale from the URL (e.g. /es/about -> 'es')
const locale = getLocaleFromPath(Astro.url.pathname) as LocalesValues;

// Get the content for the 'app' dictionary
const { title } = getIntlayer("app", locale);
---

<!doctype html>
<html lang={locale} dir={getHTMLTextDir(locale)}>
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width" />
    <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
    <title>{title}</title>

    <!-- Canonical link: Tells search engines which is the primary version of this page -->
    <link
      rel="canonical"
      href={new URL(getLocalizedUrl(Astro.url.pathname, locale), Astro.site)}
    />

    <!-- Hreflang: Tell Google about all localized versions -->
    {
      localeMap(({ locale: mapLocale }) => (
        <link
          rel="alternate"
          hreflang={mapLocale}
          href={new URL(
            getLocalizedUrl(Astro.url.pathname, mapLocale),
            Astro.site
          )}
        />
      ))
    }

    <!-- x-default: Fallback for users in unmatched languages -->
    <link
      rel="alternate"
      hreflang="x-default"
      href={new URL(
        getLocalizedUrl(Astro.url.pathname, defaultLocale),
        Astro.site
      )}
    />
  </head>
  <body>
    <header>
      <LocaleSwitcher />
    </header>
    <main>
      <h1>{title}</h1>
    </main>
  </body>
</html>
```

### Step 6: Localised Routing

Create dynamic route segments to serve localised pages (e.g., `src/pages/[locale]/index.astro`):

```astro fileName="src/pages/[locale]/index.astro"
---
import { getIntlayer } from "intlayer";

const { title } = getIntlayer('app');
---

<h1>{title}</h1>
```

The Astro integration adds a Vite middleware that helps with language-sensitive routing and environment definitions during development. You can also create links across languages using your own logic or `intlayer` tools like `getLocalizedUrl`.

### Step 7: Continue Using Your Favourite Frameworks

Keep building your application using the framework of your choice.

- Intlayer + React: [Intlayer with React](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en-GB/intlayer_with_vite+react.md)
- Intlayer + Vue: [Intlayer with Vue](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en-GB/intlayer_with_vite+vue.md)
- Intlayer + Svelte: [Intlayer with Svelte](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en-GB/intlayer_with_vite+svelte.md)
- Intlayer + Solid: [Intlayer with Solid](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en-GB/intlayer_with_vite+solid.md)
- Intlayer + Preact: [Intlayer with Preact](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en-GB/intlayer_with_vite+preact.md)

### TypeScript Configuration

Intlayer uses module augmentation to leverage TypeScript, making your codebase more robust.

![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 configuration
  "include": [
    // ... your existing TypeScript configuration
    ".intlayer/**/*.ts", // Include autogenerated types
  ],
}
```

### Git Configuration

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

To do this, 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**.

[Installation 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 preview** of translated content.
- **Quick actions** for easily creating and updating translations.

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

---

### (Optional) Step 15: 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-GB/compiler.md) / [extractor](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en-GB/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>

---

### Deepen Your Knowledge

If you want to learn more, you can also implement the [Visual Editor](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en-GB/intlayer_visual_editor.md) or use the [CMS](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en-GB/intlayer_CMS.md) to externalise your content.
