---
createdAt: 2025-04-18
updatedAt: 2026-09-27
priority: 9
title: "Vite + Svelte i18n - Complete guide to translate your app"
description: "Set up Intlayer in a Vite and Svelte app: translated content through stores, a locale switcher, localized routes and typed dictionaries."
keywords:
  - Internationalization
  - 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"
author: aymericzip
---

# Translate your Vite and Svelte website using Intlayer

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

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

  </Tab>
</Tabs>

## Table of Contents

<TOC/>

## Why Intlayer over alternatives?

Compared to main solutions like `svelte-i18n` or `i18next`, Intlayer is a solution that comes with integrated optimizations such as:

<AccordionGroup>
<Accordion header="Full Svelte coverage">

Intlayer is optimized to work perfectly with Svelte by offering **component-level content scoping**, **reactive translations**, and all the features needed for scaling internationalization (i18n).

</Accordion>
<Accordion header="Bundle size">

Instead of loading massive JSON files into your pages, load only the necessary content. Intlayer helps **reduce your bundle and page sizes by up to 50%**.

</Accordion>
<Accordion header="Maintainability">

Scoping your application's content **facilitates maintenance** for large-scale applications. You can duplicate or delete a single feature folder without the mental burden of reviewing your entire content codebase. Additionally, Intlayer is **fully typed** to ensure your content's accuracy.

</Accordion>
<Accordion header="AI Agent">

Co-locating content **reduces the context needed** by Large Language Models (LLMs). Intlayer also comes with a suite of tools, such as a **CLI** to test for missing translations,**[LSP](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/lsp.md)**, **[MCP](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/mcp_server.md)**, and **[agent skills](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/agent_skills.md)**, to make the developer experience (DX) even smoother for AI agents.

- [LSP](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/lsp.md)
- [MCP](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/mcp_server.md)
- [agent skills](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/agent_skills.md)

</Accordion>
<Accordion header="Automation">

Use automation to translate in your CI/CD pipeline using the LLM of your choice at the cost of your AI provider. Intlayer also offers a **compiler** to automate content extraction, as well as a [web platform](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_CMS.md) to help **translate in the background**.

- [web platform](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_CMS.md)

</Accordion>
<Accordion header="Performance">

Connecting massive JSON files to components can lead to performance and reactivity issues. Intlayer optimizes your content loading at build time.

</Accordion>
<Accordion header="Scaling with none-dev">

More than just an i18n solution, Intlayer provides an **self-hosted [visual editor](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_visual_editor.md)** and a **[full CMS](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_CMS.md)** to help you manage your multilingual content in **real-time**, making collaboration with translators, copywriters, and other team members seamless. Content can be stored locally and/or remotely.

- [visual editor](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_visual_editor.md)
- [full CMS](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_CMS.md)

</Accordion>
</AccordionGroup>

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

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

<Steps>
<Step number={1} title="Install Dependencies">

Install the necessary packages using npm:

```bash packageManager="npm"
npx intlayer init --interactive
```

```bash packageManager="pnpm"
pnpm dlx intlayer init --interactive
```

```bash packageManager="yarn"
yarn dlx intlayer init --interactive
```

```bash packageManager="bun"
bunx intlayer init --interactive
```

> the `--interactive` flag is optional. Use `intlayer-cli init` if you're an AI agent.

> This command will detect your environment and install the required packages. For example:

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

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

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

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

- **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).

- **svelte-intlayer**
  The package that integrates Intlayer with Svelte application. It provides context providers and hooks for Svelte 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>
<Step number={2} title="Configuration of your project">

### Architecture

In this architecture, `svelte-intlayer` provides reactive stores and utilities to manage translations within Svelte components. Content declarations live in `src/` alongside components.

```bash
.
├── src
│   ├── app.content.ts
│   ├── app.css
│   ├── App.svelte                    # Root component
│   ├── lib
│   │   ├── Counter.svelte
│   │   └── LocaleSwitcher.svelte
│   ├── main.ts                       # Entry point
│   └── vite-env.d.ts
├── index.html
├── intlayer.config.ts
├── package.json
├── svelte.config.js
├── tsconfig.json
└── vite.config.ts
```

### Configuration

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 localized 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/configuration.md).

- [configuration documentation](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/configuration.md)

</Step>
<Step number={3} title="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 optimize performance.

</Step>
<Step number={4} title="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 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,md,mdx,yaml,yml}`).

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

- [content declaration documentation](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/dictionary/content_file.md)

</Step>
<Step number={5} title="Utilize 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>
```

> 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.

- [Intlayer Compiler](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/compiler.md)
- [extract command](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/cli/extract.md)

</Step>
<Step number={6} title="Change the language of your content" isOptional={true}>

```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>
```

</Step>
<Step number={7} title="Render Markdown and HTML" isOptional={true}>

Intlayer supports rendering Markdown and HTML content in Svelte.

By default, Intlayer treats Markdown and HTML as interactive components or strings. To render them in Svelte, you can use the `{@const Component = ...}<Component />` for components or `{@html ...}` for plain strings.

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

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

<!-- Render Markdown as a Component -->
{@const MyMarkdownContent = $content.myMarkdownContent}<MyMarkdownContent />

<!-- Render HTML Content -->
{@html $content.myHtmlContent.toString()}

<!-- Render with custom component overrides -->
{@const MyMarkdownContent = $content.myMarkdownContent.use({
    h1: (props) => {
      const h1 = document.createElement('h1');
      h1.style.color = 'red';
      h1.textContent = props.children;
      return h1;
    },
    MyCustomComponent: () => {
       const div = document.createElement('div');
       div.textContent = 'Custom Logic';
       return div;
    }
  })}
<MyMarkdownContent />
```

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

</Step>
<Step number={8} title="Set up the intlayer editor / CMS" isOptional={true}>

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

- [intlayer editor documentation](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/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/intlayer_CMS.md).

- [intlayer CMS documentation](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_CMS.md)

</Step>
<Step number={7} title="Add localized Routing to your application" isOptional={true}>

To handle localized 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,
            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`.

> Since Intlayer v9, `intlayerProxy()` is bundled directly into the `intlayer()` plugin and enabled by default through the `routing.enableProxy` option (`true` by default). Registering it separately as shown below is now optional. It is kept for backward compatibility and for setups that need to control plugin order. Set `routing.enableProxy: false` to opt out. See the [v9 release notes](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/releases/v9.md).

- [v9 release notes](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/releases/v9.md)

```typescript {3,7} fileName="vite.config.ts" codeFormat={["typescript", "esm", "commonjs"]}
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({
      proxy: {
        ignore: (req) => req.url?.startsWith("/api"),
      },
    }),
  ],
});
```

</Step>
<Step number={8} title="Change the URL when the locale changes" isOptional={true}>

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>
```

</Step>
<Step number={9} title="Internationalized Links" isOptional={true}>

For SEO, it is recommended to prefix your routes with the locale (e.g., `/about`, `/fr/about`).

```svelte fileName="src/lib/components/Link.svelte"
<script lang="ts">
  import { getLocalizedUrl } from "intlayer";
  import { useLocale } from "svelte-intlayer";

  export let href = "";
  const { locale } = useLocale();

  // Helper to prefix URL
  $: localizedHref = getLocalizedUrl(href, $locale);
</script>

<a href={localizedHref}>
  <slot />
</a>
```

</Step>
<Step number={10} title="Extract the content of your components" isOptional={true}>

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.

- [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 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'>

 <Tabs>
 <Tab value='intlayer >= 9'>

> Since v9, the `intlayerCompiler` is included in the `intlayer` plugin. So you don't need to add it manually.

 </Tab>
 <Tab value='intlayer < 9'>

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
  ],
});
```

 </Tab>
 </Tabs>

Build your application to transform your components and extract the content

```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>
</Step>

</Steps>

### (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: "https://example.com",
});
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: https://example.com/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.

### 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://github.com/aymericzip/intlayer/blob/main/docs/docs/en/vs_code_extension.md).

- [Intlayer VS Code Extension documentation](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/vs_code_extension.md)

### 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).

- [visual editor](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_visual_editor.md)
- [CMS](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_CMS.md)

## Frequently Asked Questions

<FAQ>

<Question title="What are the different solutions available to internationalize a Vite and Svelte app?">

Vite has no opinion on i18n, so the choice comes from the Svelte ecosystem:

- **`svelte-i18n`** and **`typesafe-i18n`**: store based message catalogs registered globally.
- **`Paraglide`**: compiled messages, focused on the message layer only.
- **`Intlayer`**: the most advanced solution. Content declared anywhere in your codebase ([next to each component or centralized](https://github.com/aymericzip/intlayer/blob/main/docs/blog/en/per-component_vs_centralized_i18n.md)) and compiled by the Vite plugin at build time, fully typed, with AI translation, a visual editor and a CMS.

The Vite specific gain is that translations are resolved and tree shaken at compile time instead of being fetched as JSON at runtime, so a page ships only the entries it renders. See [why Intlayer](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/interest_of_intlayer.md) and the [benchmark](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/benchmark/index.md).

- [why Intlayer](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/interest_of_intlayer.md)
- [benchmark](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/benchmark/index.md)

</Question>
<Question title="How much does i18n add to my Svelte bundle size?">

Much less than a namespace based setup, because a page never downloads a catalog it does not render. The build time compiler replaces `useIntlayer` calls with the exact dictionary entries a component uses, so unused keys and unused languages are dropped, and [dynamic dictionaries](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/dynamic_dictionaries/index.md) split the rest per locale. Measured against the usual alternatives, Intlayer reduces bundle and page size by up to 50%. See [bundle optimization](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/bundle_optimization.md) and the [benchmark](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/benchmark/svelte.md).

- [dynamic dictionaries](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/dynamic_dictionaries/index.md)
- [bundle optimization](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/bundle_optimization.md)
- [benchmark](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/benchmark/svelte.md)

</Question>
<Question title="Can I migrate from `svelte-i18n` or `typesafe-i18n` without rewriting my components?">

Largely. Follow the [Svelte I18n migration guide](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/compat/svelte-i18n.md) to move the content over. You can also migrate gradually: the [sync JSON plugin](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/plugins/sync-json.md) keeps your existing JSON catalogs as the source of truth and generates Intlayer dictionaries from them, so both layers stay in sync while you move components across one at a time.

- [Svelte I18n migration guide](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/compat/svelte-i18n.md)
- [sync JSON plugin](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/plugins/sync-json.md)

</Question>
<Question title="Can I keep my existing JSON translation files?">

Yes. The [sync JSON plugin](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/plugins/sync-json.md) keeps your `/messages/{locale}/{namespace}.json` files as the source of truth and generates Intlayer dictionaries from them, in both directions. A [sync PO plugin](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/plugins/sync-po.md) does the same for gettext catalogs, and [per locale files](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/per_locale_file.md) let you split content by language instead of grouping locales in one file.

- [sync JSON plugin](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/plugins/sync-json.md)
- [sync PO plugin](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/plugins/sync-po.md)
- [per locale files](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/per_locale_file.md)

</Question>
<Question title="Do I have to move my content key by key?">

No. Run `npx intlayer extract` and Intlayer reads your components, pulls the user facing strings out and writes a `.content` file next to each one, so you review a diff instead of copying strings into a catalog one at a time. Step 10 of this guide walks through it.

For a fully automated pipeline, the [Intlayer Compiler](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/compiler.md) does the same at build time: it scans your JSX, TSX, Vue and Svelte source on every change, generates the dictionaries and keeps them in sync through hot module replacement, so there are no keys to maintain by hand at all.

- [Intlayer Compiler](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/compiler.md)

Two limits are worth knowing before you turn the compiler on. It works by static analysis, so strings that only exist at runtime, such as API error codes or CMS fields, stay out of reach. And it has to tell user facing text apart from application logic like `className="active"` or a status code, which needs a few annotations in a large codebase. The [extract command](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/cli/extract.md) avoids both by keeping you in the loop.

- [extract command](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/cli/extract.md)

</Question>
<Question title="What editor and AI agent tooling is available?">

Five pieces, all optional:

- **[VS Code extension](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/vs_code_extension.md)**: jump from a `useIntlayer` key to the content file that declares it, extract content from a component, and run build, fill, test, push and pull from the command palette or a dedicated Intlayer tab.
- **[LSP server](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/lsp.md)**: the same awareness in any editor that speaks LSP, with go to definition, find all references, hover previews of a translated value, autocompletion of keys and fields, and a warning when a key is not declared anywhere. It also resolves `i18next`, `react-i18next`, `next-intl` and `use-intl` calls, which helps while you migrate.
- **[MCP server](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/mcp_server.md)**: exposes the Intlayer documentation and CLI to Cursor, VS Code, Claude Desktop, Claude Code and ChatGPT, so an assistant answers from current docs instead of guessing, and can run commands such as `intlayer fill` itself.
- **[Agent skills](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/agent_skills.md)**: focused skills such as `intlayer-config`, `intlayer-cli` and `intlayer-content`, plus one per framework, that teach an agent your routing setup and the content node types.
- **[ESLint plugin](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/eslint.md)**: `no-raw-text` flags hardcoded strings, with further rules for static dictionary keys and unused content.

</Question>
<Question title="How do I use translated content in a Svelte component?">

Call `useIntlayer` in your component and read the returned content. The value is reactive, so changing the locale re-renders the components that use it without a page reload. Step 5 shows the component, and step 7 covers rendering Markdown and HTML content.

</Question>
<Question title="Does Intlayer work with the Vite dev server and hot reload?">

Yes. The `intlayer()` Vite plugin watches your `.content.ts` files and rebuilds the affected dictionaries on save, so edits appear without restarting the dev server, and the generated types are regenerated at the same time so autocompletion stays in sync.

</Question>
<Question title="How do I set up localized routing?">

Steps 7 and 8 cover the localized routes and rewriting the URL when the locale changes, and step 9 covers internationalized links. `routing.mode` decides the URL scheme: `"prefix-no-default"` (the default, `/about` and `/fr/about`), `"prefix-all"`, `"no-prefix"` (resolved from a cookie, a header or a domain) or `"search-params"` (`/about?locale=fr`). See the [configuration reference](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/configuration.md).

- [configuration reference](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/configuration.md)

</Question>
<Question title="How do I support right to left languages such as Arabic or Hebrew?">

Step 9 covers it. `getHTMLTextDir` returns `ltr`, `rtl` or `auto` for a locale, so you bind `lang` and `dir` on the root element from the active locale and let your CSS logical properties handle the rest.

</Question>
<Question title="How do I handle SEO metadata in a client rendered Vite app?">

Set `lang` and `dir` on the `html` element from the active locale, and emit `hreflang` alternates for every declared locale with `getMultilingualUrls`, including `x-default`. For pages that must be crawled reliably, prefer a pre-rendered or server rendered setup.

</Question>
<Question title="How do I translate the app automatically with AI?">

Run `npx intlayer fill`. It fills missing translations with the LLM of your choice, using your own provider and API key, and `--git-diff` limits the run to the content changed on the branch. See the [fill command](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/cli/fill.md) and [CI/CD integration](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/CI_CD.md).

- [fill command](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/cli/fill.md)
- [CI/CD integration](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/CI_CD.md)

</Question>
<Question title="Does Intlayer support plurals, gender and rich text?">

Yes: [plural forms](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/dictionary/plurial.md), [gender based content](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/dictionary/gender.md), conditions, [insertions](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/dictionary/insertion.md), [Markdown](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/dictionary/markdown.md) and [formatters](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/formatters.md) for numbers, dates and currencies.

- [plural forms](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/dictionary/plurial.md)
- [gender based content](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/dictionary/gender.md)
- [insertions](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/dictionary/insertion.md)
- [Markdown](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/dictionary/markdown.md)
- [formatters](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/formatters.md)

</Question>
<Question title="How can translators edit the content without touching the code?">

Through the [visual editor](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_visual_editor.md), which runs on your own infrastructure and lets anyone edit text in place on the running app, or the [CMS](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_CMS.md), which externalizes content so it can change without a deployment.

- [visual editor](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_visual_editor.md)
- [CMS](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/intlayer_CMS.md)

</Question>
<Question title="Is Intlayer free and open source?">

Yes, under the Apache 2.0 license, commercial use included. The hosted CMS is an optional paid service that can also be [self hosted](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/self_hosting.md).

- [self hosted](https://github.com/aymericzip/intlayer/blob/main/docs/docs/en/self_hosting.md)

</Question>

</FAQ>