Getting Started internationalizing (i18n) with Intlayer and Next.js 15 App Router

See Application Template on GitHub.

What is Intlayer?

Intlayer is an innovative, open-source internationalization (i18n) library designed to simplify multilingual support in modern web applications. Intlayer seamlessly integrates with the latest Next.js 15 framework, including its powerful App Router. It is optimized to work with Server Components for efficient rendering and is fully compatible with Turbopack.

With Intlayer, you can:

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

Intlayer is compatible with Next.js 12, 13, 14, and 15. If you are using Next.js Page Router, you can refer to this guide. For Next.js 12, 13, 14 with App Router, refer to this guide.

Step-by-Step Guide to Set Up Intlayer in a Next.js Application

Step 1: Install Dependencies

Install the necessary packages using npm:

npm install intlayer next-intlayer

pnpm add intlayer next-intlayer

yarn add intlayer next-intlayer

intlayer

The core package that provides internationalization tools for configuration management, translation, content declaration, transpilation, and CLI commands.
next-intlayer

The package that integrates Intlayer with Next.js. It provides context providers and hooks for Next.js internationalization. Additionally, it includes the Next.js plugin for integrating Intlayer with Webpack or Turbopack, as well as middleware for detecting the user's preferred locale, managing cookies, and handling URL redirection.

Step 2: Configure Your Project

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

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;

import { Locales } from "intlayer";

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

export default config;

const { Locales } = require("intlayer");

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

module.exports = 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.

Step 3: Integrate Intlayer in Your Next.js Configuration

Configure your Next.js setup to use Intlayer:

import type { NextConfig } from "next";
import { withIntlayer } from "next-intlayer/server";

const nextConfig: NextConfig = {
  /* config options here */
};

export default withIntlayer(nextConfig);

import { withIntlayer } from "next-intlayer/server";

/** @type {import('next').NextConfig} */
const nextConfig = {
  /* config options here */
};

export default withIntlayer(nextConfig);

const { withIntlayer } = require("next-intlayer/server");

/** @type {import('next').NextConfig} */
const nextConfig = {
  /* config options here */
};

module.exports = withIntlayer(nextConfig);

The withIntlayer() Next.js plugin is used to integrate Intlayer with Next.js. It ensures the building of content declaration files and monitors them in development mode. It defines Intlayer environment variables within the Webpack or Turbopack environments. Additionally, it provides aliases to optimize performance and ensures compatibility with server components.

Step 4: Define Dynamic Locale Routes

Remove everything from RootLayout and replace it with the following code:

import type { PropsWithChildren, FC } from "react";
import "./globals.css";

const RootLayout: FC<PropsWithChildren> = ({ children }) => children;

export default RootLayout;

import "./globals.css";

const RootLayout = ({ children }) => children;

export default RootLayout;

require("./globals.css");

const RootLayout = ({ children }) => children;

module.exports = {
  default: RootLayout,
  generateStaticParams,
};

Keeping the RootLayout component empty allows to set the lang and dir attributes to the <html> tag.

To implement dynamic routing, provide the path for the locale by adding a new layout in your [locale] directory:

import type { NextLayoutIntlayer } from "next-intlayer";
import { Inter } from "next/font/google";
import { getHTMLTextDir } from "intlayer";

const inter = Inter({ subsets: ["latin"] });

const LocaleLayout: NextLayoutIntlayer = async ({ children, params }) => {
  const { locale } = await params;
  return (
    <html lang={locale} dir={getHTMLTextDir(locale)}>
      <body className={inter.className}>{children}</body>
    </html>
  );
};

export default LocaleLayout;

import { getHTMLTextDir } from "intlayer";

const inter = Inter({ subsets: ["latin"] });

const LocaleLayout = async ({ children, params: { locale } }) => {
  const { locale } = await params;
  return (
    <html lang={locale} dir={getHTMLTextDir(locale)}>
      <body className={inter.className}>{children}</body>
    </html>
  );
};

export default LocaleLayout;

const { Inter } = require("next/font/google");
const { getHTMLTextDir } = require("intlayer");

const inter = Inter({ subsets: ["latin"] });

const LocaleLayout = async ({ children, params: { locale } }) => {
  const { locale } = await params;
  return (
    <html lang={locale} dir={getHTMLTextDir(locale)}>
      <body className={inter.className}>{children}</body>
    </html>
  );
};

module.exports = LocaleLayout;

The [locale] path segment is used to define the locale. Example: /en-US/about will refer to en-US and /fr/about to fr.

Then, implement the generateStaticParams function in your application Layout.

export { generateStaticParams } from "next-intlayer"; // Line to insert

const LocaleLayout: NextLayoutIntlayer = async ({ children, params }) => {
  /*... Rest of the code*/
};

export default LocaleLayout;

export { generateStaticParams } from "next-intlayer"; // Line to insert

const LocaleLayout = async ({ children, params: { locale } }) => {
  /*... Rest of the code*/
};

// ... Rest of the code

const { generateStaticParams } = require("next-intlayer"); // Line to insert

const LocaleLayout = async ({ children, params: { locale } }) => {
  /*... Rest of the code*/
};

module.exports = { default: LocaleLayout, generateStaticParams };

generateStaticParams ensures that your application pre-builds the necessary pages for all locales, reducing runtime computation and improving the user experience. For more details, refer to the Next.js documentation on generateStaticParams.

Step 5: Declare Your Content

Create and manage your content declarations to store translations:

import { t, type Dictionary } from "intlayer";

const pageContent = {
  key: "page",
  content: {
    getStarted: {
      main: t({
        en: "Get started by editing",
        fr: "Commencez par éditer",
        es: "Comience por editar",
      }),
      pageLink: "src/app/page.tsx",
    },
  },
} satisfies Dictionary;

export default pageContent;

import { t } from "intlayer";

/** @type {import('intlayer').Dictionary} */
const pageContent = {
  key: "page",
  content: {
    getStarted: {
      main: t({
        en: "Get started by editing",
        fr: "Commencez par éditer",
        es: "Comience por editar",
      }),
      pageLink: "src/app/page.tsx",
    },
  },
};

export default pageContent;

const { t } = require("intlayer");

/** @type {import('intlayer').Dictionary} */
const pageContent = {
  key: "page",
  content: {
    getStarted: {
      main: t({
        en: "Get started by editing",
        fr: "Commencez par éditer",
        es: "Comience por editar",
      }),
      pageLink: "src/app/page.tsx",
    },
  },
};

module.exports = pageContent;

{
  "$schema": "https://intlayer.org/schema.json",
  "key": "page",
  "content": {
    "getStarted": {
      "nodeType": "translation",
      "translation": {
        "en": "Get started by editing",
        "fr": "Commencez par éditer",
        "es": "Comience por editar"
      }
    },
    "pageLink": {
      "nodeType": "translation",
      "translation": {
        "en": "src/app/page.tsx",
        "fr": "src/app/page.tsx",
        "es": "src/app/page.tsx"
      }
    }
  }
}

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,mjx,cjs,cjx}). For more details, refer to the content declaration documentation.

Step 6: Utilize Content in Your Code

Access your content dictionaries throughout your application:

import type { FC } from "react";
import { ClientComponentExample } from "@components/ClientComponentExample";
import { ServerComponentExample } from "@components/ServerComponentExample";
import { type NextPageIntlayer, IntlayerClientProvider } from "next-intlayer";
import { IntlayerServerProvider, useIntlayer } from "next-intlayer/server";

const PageContent: FC = () => {
  const content = useIntlayer("page");

  return (
    <>
      <p>{content.getStarted.main}</p>
      <code>{content.getStarted.pageLink}</code>
    </>
  );
};

const Page: NextPageIntlayer = async ({ params }) => {
  const { locale } = await params;

  return (
    <IntlayerServerProvider locale={locale}>
      <PageContent />
      <ServerComponentExample />

      <IntlayerClientProvider locale={locale}>
        <ClientComponentExample />
      </IntlayerClientProvider>
    </IntlayerServerProvider>
  );
};

export default Page;

import { ClientComponentExample } from "@components/ClientComponentExample";
import { ServerComponentExample } from "@components/ServerComponentExample";
import { IntlayerClientProvider } from "next-intlayer";
import { IntlayerServerProvider, useIntlayer } from "next-intlayer/server";

const PageContent = () => {
  const content = useIntlayer("page");

  return (
    <>
      <p>{content.getStarted.main}</p>
      <code>{content.getStarted.pageLink}</code>
    </>
  );
};

const Page = async ({ params }) => {
  const { locale } = await params;

  return (
    <IntlayerServerProvider locale={locale}>
      <PageContent />
      <ServerComponentExample />

      <IntlayerClientProvider locale={locale}>
        <ClientComponentExample />
      </IntlayerClientProvider>
    </IntlayerServerProvider>
  );
};

export default Page;

import { ClientComponentExample } from "@components/ClientComponentExample";
import { ServerComponentExample } from "@components/ServerComponentExample";
import { IntlayerClientProvider } from "next-intlayer";
import { IntlayerServerProvider, useIntlayer } from "next-intlayer/server";

const PageContent = () => {
  const content = useIntlayer("page");

  return (
    <>
      <p>{content.getStarted.main}</p>
      <code>{content.getStarted.pageLink}</code>
    </>
  );
};

const Page = async ({ params }) => {
  const { locale } = await params;

  return (
    <IntlayerServerProvider locale={locale}>
      <PageContent />
      <ServerComponentExample />

      <IntlayerClientProvider locale={locale}>
        <ClientComponentExample />
      </IntlayerClientProvider>
    </IntlayerServerProvider>
  );
};

IntlayerClientProvider is used to provide the locale to client-side components. It can be placed in any parent component, including the layout. However, placing it in a layout is recommended because Next.js shares layout code across pages, making it more efficient. By using IntlayerClientProvider in the layout, you avoid reinitializing it for every page, improving performance and maintaining a consistent localization context throughout your application.
IntlayerServerProvider is used to provide the locale to the server children. It cannot be set set in the layout.

Layout and page cannot share a common server context because the server context system is based on a per-request data store (via React’s cache mechanism), causing each “context” to be re-created for different segments of the application. Placing the provider in a shared layout would break this isolation, preventing the correct propagation of the server context values to your server components.

"use client";

import type { FC } from "react";
import { useIntlayer } from "next-intlayer";

export const ClientComponentExample: FC = () => {
  const content = useIntlayer("client-component-example"); // Create related content declaration

  return (
    <div>
      <h2>{content.title} </h2>
      <p>{content.content}</p>
    </div>
  );
};

"use client";

import { useIntlayer } from "next-intlayer";

const ClientComponentExample = () => {
  const content = useIntlayer("client-component-example"); // Create related content declaration

  return (
    <div>
      <h2>{content.title} </h2>
      <p>{content.content}</p>
    </div>
  );
};

"use client";

const { useIntlayer } = require("next-intlayer");

const ClientComponentExample = () => {
  const content = useIntlayer("client-component-example"); // Create related content declaration

  return (
    <div>
      <h2>{content.title} </h2>
      <p>{content.content}</p>
    </div>
  );
};

import type { FC } from "react";
import { useIntlayer } from "next-intlayer/server";

export const ServerComponentExample: FC = () => {
  const content = useIntlayer("server-component-example"); // Create related content declaration

  return (
    <div>
      <h2>{content.title} </h2>
      <p>{content.content}</p>
    </div>
  );
};

import { useIntlayer } from "next-intlayer/server";

const ServerComponentExample = () => {
  const content = useIntlayer("server-component-example"); // Create related content declaration

  return (
    <div>
      <h2>{content.title} </h2>
      <p>{content.content}</p>
    </div>
  );
};

const { useIntlayer } = require("next-intlayer/server");

const ServerComponentExample = () => {
  const content = useIntlayer("server-component-example"); // Create related content declaration

  return (
    <div>
      <h2>{content.title} </h2>
      <p>{content.content}</p>
    </div>
  );
};

If you want to use your content in a string attribute, such as alt, title, href, aria-label, etc., you must call the value of the function, like:
<img src={content.image.src.value} alt={content.image.value} />

To Learn more about the useIntlayer hook, refer to the documentation.

(Optional) Step 7: Configure Middleware for Locale Detection

Set up middleware to detect the user's preferred locale:

export { intlayerMiddleware as middleware } from "next-intlayer/middleware";

export const config = {
  matcher:
    "/((?!api|static|assets|robots|sitemap|sw|service-worker|manifest|.*\\..*|_next).*)",
};

export { intlayerMiddleware as middleware } from "next-intlayer/middleware";

export const config = {
  matcher:
    "/((?!api|static|assets|robots|sitemap|sw|service-worker|manifest|.*\\..*|_next).*)",
};

const { intlayerMiddleware } = require("next-intlayer/middleware");

const config = {
  matcher:
    "/((?!api|static|assets|robots|sitemap|sw|service-worker|manifest|.*\\..*|_next).*)",
};

module.exports = { middleware: intlayerMiddleware, config };

The intlayerMiddleware is used to detect the user's preferred locale and redirect them to the appropriate URL as specified in the configuration. Additionally, it enables saving the user's preferred locale in a cookie.

(Optional) Step 8: Internationalization of your metadata

In the case you want to internationalize your metadata, such as the title of your page, you can use the generateMetadata function provided by Next.js. Inside the function use the getTranslation function to translate your metadata.

import {
  type IConfigLocales,
  getTranslation,
  getMultilingualUrls,
} from "intlayer";
import type { Metadata } from "next";
import type { LocalPromiseParams } from "next-intlayer";

export const generateMetadata = async ({
  params,
}: LocalPromiseParams): Promise<Metadata> => {
  const { locale } = await params;
  const t = <T>(content: IConfigLocales<T>) => getTranslation(content, locale);

  /**
   * Generates an object containing all url for each locale.
   *
   * Example:
   * ```ts
   *  getMultilingualUrls('/about');
   *
   *  // Returns
   *  // {
   *  //   en: '/about',
   *  //   fr: '/fr/about',
   *  //   es: '/es/about',
   *  // }
   * ```
   */
  const multilingualUrls = getMultilingualUrls("/");

  return {
    title: t<string>({
      en: "My title",
      fr: "Mon titre",
      es: "Mi título",
    }),
    description: t({
      en: "My description",
      fr: "Ma description",
      es: "Mi descripción",
    }),
    alternates: {
      canonical: multilingualUrls[locale as keyof typeof multilingualUrls],
      languages: { ...multilingualUrls, "x-default": "/" },
    },
    openGraph: {
      url: multilingualUrls[locale],
    },
  };
};

// ... Rest of the code

import { getTranslation, getMultilingualUrls } from "intlayer";

export const generateMetadata = async ({ params }) => {
  const { locale } = await params;
  const t = (content) => getTranslation(content, locale);

  /**
   * Generates an object containing all url for each locale.
   *
   * Example:
   * ```ts
   *  getMultilingualUrls('/about');
   *
   *  // Returns
   *  // {
   *  //   en: '/about',
   *  //   fr: '/fr/about',
   *  //   es: '/es/about'
   *  // }
   * ```
   */
  const multilingualUrls = getMultilingualUrls("/");

  return {
    title: t({
      en: "My title",
      fr: "Mon titre",
      es: "Mi título",
    }),
    description: t({
      en: "My description",
      fr: "Ma description",
      es: "Mi descripción",
    }),
    alternates: {
      canonical: multilingualUrls[locale],
      languages: { ...multilingualUrls, "x-default": "/" },
    },
    openGraph: {
      url: multilingualUrls[locale],
    },
  };
};

// ... Rest of the code

const { getTranslation, getMultilingualUrls } = require("intlayer");

const generateMetadata = async ({ params }) => {
  const { locale } = await params;

  const t = (content) => getTranslation(content, locale);

  /**
   * Generates an object containing all url for each locale.
   *
   * Example:
   * ```ts
   *  getMultilingualUrls('/about');
   *
   *  // Returns
   *  // {
   *  //   en: '/about',
   *  //   fr: '/fr/about',
   *  //   es: '/es/about'
   *  // }
   * ```
   */
  const multilingualUrls = getMultilingualUrls("/");

  return {
    title: t({
      en: "My title",
      fr: "Mon titre",
      es: "Mi título",
    }),
    description: t({
      en: "My description",
      fr: "Ma description",
      es: "Mi descripción",
    }),
    alternates: {
      canonical: multilingualUrls[locale],
      languages: { ...multilingualUrls, "x-default": "/" },
    },
    openGraph: {
      url: multilingualUrls[locale],
    },
  };
};

module.exports = { generateMetadata };

// ... Rest of the code

Learn more about the metadata optimization on the official Next.js documentation.

(Optional) Step 9: Internationalization of your sitemap.xml and robots.txt

To internationalize your sitemap.xml and robots.txt, you can use the getMultilingualUrls function provided by Intlayer. This function allows you to generate multilingual URLs for your sitemap.

import { getMultilingualUrls } from "intlayer";
import type { MetadataRoute } from "next";

const sitemap = (): MetadataRoute.Sitemap => [
  {
    url: "https://example.com",
    alternates: {
      languages: { ...getMultilingualUrls("https://example.com") },
    },
  },
  {
    url: "https://example.com/login",
    alternates: {
      languages: { ...getMultilingualUrls("https://example.com/login") },
    },
  },
  {
    url: "https://example.com/register",
    alternates: {
      languages: { ...getMultilingualUrls("https://example.com/register") },
    },
  },
];

export default sitemap;

import { getMultilingualUrls } from "intlayer";

const sitemap = () => [
  {
    url: "https://example.com",
    alternates: {
      languages: { ...getMultilingualUrls("https://example.com") },
    },
  },
  {
    url: "https://example.com/login",
    alternates: {
      languages: { ...getMultilingualUrls("https://example.com/login") },
    },
  },
  {
    url: "https://example.com/register",
    alternates: {
      languages: { ...getMultilingualUrls("https://example.com/register") },
    },
  },
];

export default sitemap;

const { getMultilingualUrls } = require("intlayer");

const sitemap = () => [
  {
    url: "https://example.com",
    alternates: {
      languages: { ...getMultilingualUrls("https://example.com") },
    },
  },
  {
    url: "https://example.com/login",
    alternates: {
      languages: { ...getMultilingualUrls("https://example.com/login") },
    },
  },
  {
    url: "https://example.com/register",
    alternates: {
      languages: { ...getMultilingualUrls("https://example.com/register") },
    },
  },
];

module.exports = sitemap;

import type { MetadataRoute } from "next";
import { getMultilingualUrls } from "intlayer";

const getAllMultilingualUrls = (urls: string[]) =>
  urls.flatMap((url) => Object.values(getMultilingualUrls(url)) as string[]);

const robots = (): MetadataRoute.Robots => ({
  rules: {
    userAgent: "*",
    allow: ["/"],
    disallow: getAllMultilingualUrls(["/login", "/register"]),
  },
  host: "https://example.com",
  sitemap: `https://example.com/sitemap.xml`,
});

export default robots;

import { getMultilingualUrls } from "intlayer";

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

const robots = () => ({
  rules: {
    userAgent: "*",
    allow: ["/"],
    disallow: getAllMultilingualUrls(["/login", "/register"]),
  },
  host: "https://example.com",
  sitemap: `https://example.com/sitemap.xml`,
});

export default robots;

const { getMultilingualUrls } = require("intlayer");

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

const robots = () => ({
  rules: {
    userAgent: "*",
    allow: ["/"],
    disallow: getAllMultilingualUrls(["/login", "/register"]),
  },
  host: "https://example.com",
  sitemap: `https://example.com/sitemap.xml`,
});

module.exports = robots;

Learn more about the sitemap optimization on the official Next.js documentation. Learn more about the robots.txt optimization on the official Next.js documentation.

(Optional) Step 10: 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.

"use client";

import type { FC } from "react";
import {
  Locales,
  getHTMLTextDir,
  getLocaleName,
  getLocalizedUrl,
} from "intlayer";
import { useLocale } from "next-intlayer";
import Link from "next/link";

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

  return (
    <div>
      <button popoverTarget="localePopover">{getLocaleName(locale)}</button>
      <div id="localePopover" popover="auto">
        {availableLocales.map((localeItem) => (
          <Link
            href={getLocalizedUrl(pathWithoutLocale, localeItem)}
            hrefLang={localeItem}
            key={localeItem}
            aria-current={locale === localeItem ? "page" : undefined}
            onClick={(e) => {
              e.preventDefault();
              setLocale(localeItem);
            }}
          >
            <span>
              {/* Locale - e.g. FR */}
              {localeItem}
            </span>
            <span>
              {/* Language in its own Locale - e.g. Français */}
              {getLocaleName(localeItem, locale)}
            </span>
            <span dir={getHTMLTextDir(localeItem)} lang={localeItem}>
              {/* Language in current Locale - e.g. Francés with current locale set to Locales.SPANISH */}
              {getLocaleName(localeItem)}
            </span>
            <span dir="ltr" lang={Locales.ENGLISH}>
              {/* Language in English - e.g. French */}
              {getLocaleName(localeItem, Locales.ENGLISH)}
            </span>
          </Link>
        ))}
      </div>
    </div>
  );
};

"use client";

import {
  Locales,
  getHTMLTextDir,
  getLocaleName,
  getLocalizedUrl,
} from "intlayer";
import { useLocale } from "next-intlayer";
import Link from "next/link";

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

  return (
    <div>
      <button popoverTarget="localePopover">{getLocaleName(locale)}</button>
      <div id="localePopover" popover="auto">
        {availableLocales.map((localeItem) => (
          <Link
            href={getLocalizedUrl(pathWithoutLocale, localeItem)}
            hrefLang={localeItem}
            key={localeItem}
            aria-current={locale === localeItem ? "page" : undefined}
            onClick={(e) => {
              e.preventDefault();
              setLocale(localeItem);
            }}
          >
            <span>
              {/* Locale - e.g. FR */}
              {localeItem}
            </span>
            <span>
              {/* Language in its own Locale - e.g. Français */}
              {getLocaleName(localeItem, locale)}
            </span>
            <span dir={getHTMLTextDir(localeItem)} lang={localeItem}>
              {/* Language in current Locale - e.g. Francés with current locale set to Locales.SPANISH */}
              {getLocaleName(localeItem)}
            </span>
            <span dir="ltr" lang={Locales.ENGLISH}>
              {/* Language in English - e.g. French */}
              {getLocaleName(localeItem, Locales.ENGLISH)}
            </span>
          </Link>
        ))}
      </div>
    </div>
  );
};

"use client";

const {
  Locales,
  getHTMLTextDir,
  getLocaleName,
  getLocalizedUrl,
} = require("intlayer");
const { useLocale } = require("next-intlayer");
const Link = require("next/link");

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

  return (
    <div>
      <button popoverTarget="localePopover">{getLocaleName(locale)}</button>
      <div id="localePopover" popover="auto">
        {availableLocales.map((localeItem) => (
          <Link
            href={getLocalizedUrl(pathWithoutLocale, localeItem)}
            hrefLang={localeItem}
            key={localeItem}
            aria-current={locale === localeItem ? "page" : undefined}
            onClick={(e) => {
              e.preventDefault();
              setLocale(localeItem);
            }}
          >
            <span>
              {/* Locale - e.g. FR */}
              {localeItem}
            </span>
            <span>
              {/* Language in its own Locale - e.g. Français */}
              {getLocaleName(localeItem, locale)}
            </span>
            <span dir={getHTMLTextDir(localeItem)} lang={localeItem}>
              {/* Language in current Locale - e.g. Francés with current locale set to Locales.SPANISH */}
              {getLocaleName(localeItem)}
            </span>
            <span dir="ltr" lang={Locales.ENGLISH}>
              {/* Language in English - e.g. French */}
              {getLocaleName(localeItem, Locales.ENGLISH)}
            </span>
          </Link>
        ))}
      </div>
    </div>
  );
};

Documentation references:

useLocale hook

getLocaleName hook

getLocalizedUrl hook

getHTMLTextDir hook

hrefLang attribute

lang attribute

dir attribute

aria-current attribute

(Optional) Step 11: 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, so that. For example, when a French-speaking user clicks on a link to the "About" page, they are redirected to /fr/about instead of /about.

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, making your codebase easier to maintain and extend as your application grows.

Below is the implementation of a localized Link component in TypeScript:

"use client";

import { getLocalizedUrl } from "intlayer";
import NextLink, { type LinkProps as NextLinkProps } from "next/link";
import { useLocale } from "next-intlayer";
import type { PropsWithChildren, FC } from "react";

/**
 * 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: FC<PropsWithChildren<NextLinkProps>> = ({
  href,
  children,
  ...props
}) => {
  const { locale } = useLocale();
  const isExternalLink = checkIsExternalLink(href.toString());

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

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

"use client";

import { getLocalizedUrl } from "intlayer";
import NextLink from "next/link";
import { useLocale } from "next-intlayer";

/**
 * 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) => /^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 = ({ href, children, ...props }) => {
  const { locale } = useLocale();
  const isExternalLink = checkIsExternalLink(href.toString());

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

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

"use client";

const { getLocalizedUrl } = require("intlayer");
const NextLink = require("next/link");
const { useLocale } = require("next-intlayer");

/**
 * Utility function to check whether a given URL is external.
 * If the URL starts with http:// or https://, it's considered external.
 */
const checkIsExternalLink = (href) => /^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.
 */
const Link = ({ href, children, ...props }) => {
  const { locale } = useLocale();
  const isExternalLink = checkIsExternalLink(href.toString());

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

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

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.

By integrating this Link component across your application, you maintain a coherent and language-aware user experience while also benefitting from improved SEO and usability.

Configure TypeScript

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

Ensure your TypeScript configuration includes the autogenerated types.

{
  // ... Your existing TypeScript configurations
  "include": [
    // ... Your existing TypeScript configurations
    ".intlayer/**/*.ts", // Include the auto-generated types
  ],
}

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:

# 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

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.

Go Further

To go further, you can implement the visual editor or externalize your content using the CMS.

Provide feedback

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intlayer_with_nextjs_15.md

intlayer_with_nextjs_15.md

Getting Started internationalizing (i18n) with Intlayer and Next.js 15 App Router

What is Intlayer?

Step-by-Step Guide to Set Up Intlayer in a Next.js Application

Step 1: Install Dependencies

Step 2: Configure Your Project

Step 3: Integrate Intlayer in Your Next.js Configuration

Step 4: Define Dynamic Locale Routes

Step 5: Declare Your Content

Step 6: Utilize Content in Your Code

(Optional) Step 7: Configure Middleware for Locale Detection

(Optional) Step 8: Internationalization of your metadata

(Optional) Step 9: Internationalization of your sitemap.xml and robots.txt

(Optional) Step 10: Change the language of your content

(Optional) Step 11: Creating a Localized Link Component

How It Works

Configure TypeScript

Git Configuration

VS Code Extension

Go Further

Files

intlayer_with_nextjs_15.md

Latest commit

History

intlayer_with_nextjs_15.md

File metadata and controls

Getting Started internationalizing (i18n) with Intlayer and Next.js 15 App Router

What is Intlayer?

Step-by-Step Guide to Set Up Intlayer in a Next.js Application

Step 1: Install Dependencies

Step 2: Configure Your Project

Step 3: Integrate Intlayer in Your Next.js Configuration

Step 4: Define Dynamic Locale Routes

Step 5: Declare Your Content

Step 6: Utilize Content in Your Code

(Optional) Step 7: Configure Middleware for Locale Detection

(Optional) Step 8: Internationalization of your metadata

(Optional) Step 9: Internationalization of your sitemap.xml and robots.txt

(Optional) Step 10: Change the language of your content

(Optional) Step 11: Creating a Localized Link Component

How It Works

Configure TypeScript

Git Configuration

VS Code Extension

Go Further