Next.js Quickstart

Easily internationalize your Next.js App with gt-next

Prerequisites: Next.js App Router, basic JavaScript knowledge

Installation

Install the gt-next and gtx-cli packages:

npm i gt-next gtx-cli
yarn add gt-next
yarn add --dev gtx-cli
bun add gt-next
bun add --dev gtx-cli
pnpm add gt-next
pnpm add --save-dev gtx-cli

Quick Setup: Try npx gtx-cli@latest for automatic configuration. See the Setup Wizard guide or use our AI tools integration.

Configuration

withGTConfig

The withGTConfig function initializes the SDK in your Next.js application. Add it to your next.config.[js|ts] file:

next.config.ts
import { withGTConfig } from 'gt-next/config';

const nextConfig = {
  // Your existing Next.js config
};

export default withGTConfig(nextConfig. {
  // Additional GT configuration options
});

GTProvider

The GTProvider component provides translation context to client-side components. It manages locale state, translations, and enables the useGT and useTranslations hooks.

Add the GTProvider to your root layout(s):

app/layout.tsx
import { GTProvider } from 'gt-next';

export default function RootLayout({ children }) {
  return (
    <html>
      <body>
        <GTProvider>
          {children}
        </GTProvider>
      </body>
    </html>
  );
}

Create a gt.config.json file in your project root:

gt.config.json
{
  "defaultLocale": "en",
  "locales": ["fr", "es", "de"]
}

Customize the locales for your project. See supported locales for options.

Environment Variables

Add to your .env.local file for development hot-reloading:

.env.local
GT_API_KEY="your-dev-api-key"
GT_PROJECT_ID="your-project-id"

Development only: Don't set GT_API_KEY in production - it's only for development hot-reloading.

Get your free API keys at dash.generaltranslation.com or run:

npx gtx-cli auth


Usage

Now you can start internationalizing your content. There are two main approaches:

JSX Content with <T>

Wrap JSX elements to translate them using the <T> component:

import { T } from 'gt-next';

function Welcome() {
  return (
    <T>
      <h1>Welcome to our app!</h1>
    </T>
  );
}

For dynamic content, use variable components like <Var>:

import { T, Var } from 'gt-next';

function Greeting({ user }) {
  return (
    <T>
      <p>Hello, <Var>{user.name}</Var>!</p>
    </T>
  );
}

See the guide on using the <T> component for more information.

Plain Strings with useGT

For attributes, labels, and plain text using the useGT hook:

import { useGT } from 'gt-next';

function ContactForm() {
  const t = useGT();
  
  return (
    <input 
      placeholder={t('Enter your email')}
      aria-label={t('Email input field')}
    />
  );
}

For server components, use getGT instead of useGT.

See the guide on translating strings for more information.


Testing Your App

Test your translations by switching languages:

  1. Add a locale selection dropdown using <LocaleSelector>:

    import { LocaleSelector } from 'gt-next';
    
    function App() {
      return <LocaleSelector />;
    }
  2. Start your dev server:

    npm run dev 
    yarn run dev 
    bun run dev 
    pnpm run dev 
  3. Visit localhost:3000 and change languages via the locale selection dropdown.

In development, translations happen on-demand (you'll see a brief loading time). In production, everything is pre-translated.

Troubleshooting


Deployment

For production, you need to pre-translate content since runtime translation is disabled (except for <Tx> and tx functions).

  1. Get a production API key from dash.generaltranslation.com.

    Production keys begin with gtx-api- (different from dev keys which start with gtx-dev-). Learn more about environment differences.

  2. Add to your CI/CD environment:

    GT_PROJECT_ID=your-project-id
    GT_API_KEY=gtx-api-your-production-key

    Never prefix production keys with NEXT_PUBLIC_ - they should remain server-side only.

  3. Run the translate command to translate your content:

    npx gtx-cli translate

    You can configure the behavior of the translate command with the gt.config.json file.

    See the CLI Tool reference guide for more information.

  4. Update your build script to translate before building:

    package.json
    {
      "scripts": {
        "build": "npx gtx-cli translate && <...YOUR_BUILD_COMMAND...>"
      }
    }

Next Steps

How is this guide?

Next.js Quickstart