---
createdAt: 2025-04-18
updatedAt: 2026-05-06
title: Vite + Svelte i18n - How to translate an Svelte app in 2026
description: Discover how to make your Vite and Svelte website multilingual. Follow the documentation to internationalise (i18n) and translate it.
keywords:
  - Internationalisation
  - Documentation
  - Intlayer
  - Vite
  - Svelte
  - JavaScript
slugs:
  - doc
  - environment
  - vite-and-svelte
applicationTemplate: https://github.com/aymericzip/intlayer-vite-svelte-template
applicationShowcase: https://intlayer-vite-svelte-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: 5.5.11
    date: 2025-11-19
    changes: "Update documentation"
  - version: 5.5.10
    date: 2025-06-29
    changes: "Initial history"
---

# Translate your Vite and Svelte website using Intlayer | Internationalisation (i18n)

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  src="https://ide.intlayer.org/aymericzip/intlayer-vite-svelte-template?file=intlayer.config.ts"
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  loading="lazy"
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## 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:

- **Easily manage translations** using declarative dictionaries at the component level.
- **Dynamically localise 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 Svelte Application

<iframe
  src="https://ide.intlayer.org/aymericzip/intlayer-vite-react-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 using Intlayer"
  sandbox="allow-forms allow-modals allow-popups allow-presentation allow-same-origin allow-scripts"
  loading="lazy"
/>

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

### Step 1: Install Dependencies

Install the necessary packages using npm:

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

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

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

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

- **intlayer**

  The core package that provides internationalisation tools for configuration management, translation, [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).

- **svelte-intlayer**
  The package that integrates Intlayer with Svelte applications. It provides context providers and hooks for Svelte internationalisation.

- **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"
import { Locales, type IntlayerConfig } from "intlayer";

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

export default config;
```

> Through this configuration file, you can set up localised URLs, middleware redirection, 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-GB/configuration.md).

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

Add the intlayer plugin into your configuration.

```typescript fileName="vite.config.ts"
import { defineConfig } from "vite";
import { svelte } from "@sveltejs/vite-plugin-svelte";
import { intlayer } from "vite-intlayer";

// https://vitejs.dev/config/
export default defineConfig({
  plugins: [svelte(), 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 optimise 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";

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

export default appContent;
```

```json fileName="src/app.content.json" contentDeclarationFormat="json"
{
  "$schema": "https://intlayer.org/schema.json",
  "key": "app",
  "content": {
    "title": {
      "nodeType": "translation",
      "translation": {
        "en": "Hello World",
        "fr": "Bonjour le monde",
        "es": "Hola mundo"
      }
    }
  }
}
```

> Your content declarations can be defined anywhere in your application as soon as they are included in 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-GB/dictionary/content_file.md).

### Step 5: Utilise Intlayer in Your Code

```svelte fileName="src/App.svelte"
<script>
  import { useIntlayer } from "svelte-intlayer";

  const content = useIntlayer("app");
</script>

<div>


<!-- Render content as simple content  -->
<h1>{$content.title}</h1>
<!-- To render the content editable using the editor -->
<h1>{@const Title = $content.title}<Title /></h1>
<!-- To render the content as a string -->
<div aria-label={$content.title.value}></div>
<div aria-label={$content.title.toString()}></div>
<div aria-label={String($content.title)}></div>
```

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

```svelte fileName="src/App.svelte"
<script lang="ts">
import  { getLocaleName } from 'intlayer';
import { useLocale } from "svelte-intlayer";

// Get locale information and setLocale function
const { locale, availableLocales, setLocale } = useLocale();

// Handle locale change
const changeLocale = (event: Event) => {
  const target = event.target as HTMLSelectElement;
  const newLocale = target.value;
  setLocale(newLocale);
};
</script>

<div>
  <select value={$locale} on:change={changeLocale}>
    {#each availableLocales ?? [] as loc}
      <option value={loc}>
        {getLocaleName(loc)}
      </option>
    {/each}
  </select>
</div>
```

### (Optional) Step 7: Render Markdown

Intlayer supports rendering Markdown content directly in your Svelte application. By default, Markdown is treated as plain text. To convert Markdown into rich HTML, you can integrate `@humanspeak/svelte-markdown`, or another markdown parser.

> To see how to declare markdown content using the `intlayer` package, see the [markdown doc](https://github.com/aymericzip/intlayer/tree/main/docs/docs/en-GB/dictionary/markdown.md).

```svelte fileName="src/App.svelte"
<script>
  import { setIntlayerMarkdown } from "svelte-intlayer";

  setIntlayerMarkdown((markdown) =>
   // render the markdown content as a string
   return markdown;
  );
</script>

<h1>{$content.markdownContent}</h1>
```

> You can also access your markdown front-matter data using the `content.markdownContent.metadata.xxx` property.

### (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.

### (Optional) Step 8: Set up the intlayer editor / CMS

To set up the intlayer editor, you must follow the [intlayer editor documentation](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en-GB/intlayer_visual_editor.md).

To set up the intlayer CMS, you must follow the [intlayer CMS documentation](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en-GB/intlayer_CMS.md).

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

To handle localised routing in your Svelte application, you can use `svelte-spa-router` along with Intlayer's `localeFlatMap` to generate routes for each locale.

First, install `svelte-spa-router`:

```bash packageManager="npm"
npm install svelte-spa-router
npx intlayer init
```

```bash packageManager="pnpm"
pnpm add svelte-spa-router
pnpm intlayer init
```

```bash packageManager="yarn"
yarn add svelte-spa-router
yarn intlayer init
```

```bash packageManager="bun"
bun add svelte-spa-router
```

Then, create a `Router.svelte` file to define your routes:

```svelte fileName="src/Router.svelte"
<script lang="ts">
import { localeFlatMap } from "intlayer";
import Router from "svelte-spa-router";
import { wrap } from "svelte-spa-router/wrap";
import App from "./App.svelte";

const routes = Object.fromEntries(
    localeFlatMap(({locale, urlPrefix}) => [
    [
        urlPrefix || '/',
        wrap({
            component: App as any,
            props: {
                locale,
            },
        }),
    ],
    ])
);
</script>

<Router {routes} />
```

Update your `main.ts` to mount the `Router` component instead of `App`:

```typescript fileName="src/main.ts"
import { mount } from "svelte";
import Router from "./Router.svelte";

const app = mount(Router, {
  target: document.getElementById("app")!,
});

export default app;
```

Finally, update your `App.svelte` to receive the `locale` prop and use it with `useIntlayer`:

```svelte fileName="src/App.svelte"
<script lang="ts">
import type { Locale } from 'intlayer';
import { useIntlayer } from "svelte-intlayer";
import Counter from './lib/Counter.svelte';
import LocaleSwitcher from './lib/LocaleSwitcher.svelte';

export let locale: Locale;

$: content = useIntlayer('app', locale);
</script>

<main>
  <div class="locale-switcher-container">
    <LocaleSwitcher currentLocale={locale} />
  </div>

  <!-- ... rest of your app ... -->
</main>
```

#### Configure Server-Side Routing (Optional)

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" codeFormat={["typescript", "esm", "commonjs"]}
import { defineConfig } from "vite";
import { svelte } from "@sveltejs/vite-plugin-svelte";
import { intlayer, intlayerProxy } from "vite-intlayer";

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

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

To allow users to switch languages and update the URL accordingly, you can create a `LocaleSwitcher` component. This component will use `getLocalizedUrl` from `intlayer` and `push` from `svelte-spa-router`.

```svelte fileName="src/lib/LocaleSwitcher.svelte"
<script lang="ts">
import { getLocaleName, getLocalizedUrl } from "intlayer";
import { useLocale } from "svelte-intlayer";
import { push } from "svelte-spa-router";

export let currentLocale: string | undefined = undefined;

// Get locale information
const { locale, availableLocales } = useLocale();

// Handle locale change
const changeLocale = (event: Event) => {
  const target = event.target as HTMLSelectElement;
  const newLocale = target.value;
  const currentUrl = window.location.pathname;
  const url = getLocalizedUrl(currentUrl, newLocale);
  push(url);
};
</script>

<div class="locale-switcher">
  <select value={currentLocale ?? $locale} onchange={changeLocale}>
    {#each availableLocales ?? [] as loc}
      <option value={loc}>
        {getLocaleName(loc)}
      </option>
    {/each}
  </select>
</div>
```

### Git Configuration

It is recommended to ignore the files generated by Intlayer. This prevents you from 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-GB/intlayer_visual_editor.md) or externalise your content using the [CMS](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en-GB/intlayer_CMS.md).
