Setup

ℹ️

Make sure you've followed the Get Started documentation before continuing!

Create locale files

Create locales/client.ts and locales/server.ts with your locales:

// locales/client.ts
"use client"
import { createI18nClient } from 'next-international/client'
 
export const { useI18n, useScopedI18n, I18nProviderClient } = createI18nClient({
  en: () => import('./en'),
  fr: () => import('./fr')
})
 
// locales/server.ts
import { createI18nServer } from 'next-international/server'
 
export const { getI18n, getScopedI18n, getStaticParams } = createI18nServer({
  en: () => import('./en'),
  fr: () => import('./fr')
})

Each locale file should export a default object (don't forget as const):

// locales/en.ts
export default {
  'hello': 'Hello',
  'hello.world': 'Hello world!',
  'welcome': 'Hello {name}!'
} as const

Move your existing files

Move all your routes inside an app/[locale]/ folder. For Client Components, wrap the lowest parts of your app with I18nProviderClient inside a layout:

// app/[locale]/client/layout.tsx
import { ReactElement } from 'react'
import { I18nProviderClient } from '../../locales/client'
 
// If you are using Next.js < 15, you don't need to await `params`:
// export default function SubLayout({ params: { locale }, children }: { params: { locale: string }, children: ReactElement }) {
export default function SubLayout({ params, children }: { params: Promise<{ locale: string }>, children: ReactElement }) {
  const { locale } = await params
 
  return (
    <I18nProviderClient locale={locale}>
      {children}
    </I18nProviderClient>
  )
}

You can also provide a fallback component prop to show while waiting for the locale to load.

Setup middleware

Add a middleware.ts file at the root of your app, that will redirect the user to the right locale. You can also rewrite the URL to hide the locale:

// middleware.ts
import { createI18nMiddleware } from 'next-international/middleware'
import { NextRequest } from 'next/server'
 
const I18nMiddleware = createI18nMiddleware({
  locales: ['en', 'fr'],
  defaultLocale: 'en'
})
 
export function middleware(request: NextRequest) {
  return I18nMiddleware(request)
}
 
export const config = {
  matcher: ['/((?!api|static|.*\\..*|_next|favicon.ico|robots.txt).*)']
}

Translate

Use useI18n and useScopedI18n() / getI18n and getScopedI18n() inside your components:

// Client Component
'use client'
import { useI18n, useScopedI18n } from '../../locales/client'
 
export default function Page() {
  const t = useI18n()
  const scopedT = useScopedI18n('hello')
 
  return (
    <div>
      <p>{t('hello')}</p>
 
      {/* Both are equivalent: */}
      <p>{t('hello.world')}</p>
      <p>{scopedT('world')}</p>
 
      <p>{t('welcome', { name: 'John' })}</p>
      <p>{t('welcome', { name: <strong>John</strong> })}</p>
    </div>
  )
}
 
// Server Component
import { getI18n, getScopedI18n } from '../../locales/server'
 
export default async function Page() {
  const t = await getI18n()
  const scopedT = await getScopedI18n('hello')
 
  return (
    <div>
      <p>{t('hello')}</p>
 
      {/* Both are equivalent: */}
      <p>{t('hello.world')}</p>
      <p>{scopedT('world')}</p>
 
      <p>{t('welcome', { name: 'John' })}</p>
      <p>{t('welcome', { name: <strong>John</strong> })}</p>
    </div>
  )
}

What's next?

Learn how to add plurals, use scoped translations, setup Static Rendering, and tweak the middleware configuration.

Examples Plurals