Nextjs with next-intl: The Double Rendering Conundrum

Are you struggling with Nextjs and next-intl, only to find that your page is rendering twice? You’re not alone! This mysterious phenomenon has left many developers scratching their heads, wondering what’s going on behind the scenes. Fear not, dear reader, for we’re about to dive into the depths of this issue and emerge with a solution that will make your head spin (in a good way, of course)!

The Problem: Double Rendering with Nextjs and next-intl

So, what’s the big deal? Why does Nextjs, an otherwise fantastic framework, decide to render your page twice when using next-intl for internationalization? It’s not a bug, per se, but rather a misunderstanding of how these two powerful tools interact. Let’s break it down:

• Nextjs: A popular React-based framework for building server-side rendered (SSR) and statically generated websites and applications. It’s fast, efficient, and SEO-friendly.
• next-intl: A plugin for Nextjs that enables seamless internationalization (i18n) and localization (L10n) of your application. It’s a game-changer for going global!

The issue arises when you combine these two powerhouses. Nextjs, by default, uses server-side rendering (SSR) to pre-render your pages at build time. Next-intl, on the other hand, relies on client-side rendering (CSR) to inject locale-specific translations and formatting. When these two approaches clash, you get… (drumroll please)… double rendering!

The Cause: A Tale of Two Rendering Modes

Let’s explore the two rendering modes at play:

Rendering Mode	Description
Server-Side Rendering (SSR)	Nextjs pre-renders pages at build time, generating static HTML files that can be served directly by a web server.
Client-Side Rendering (CSR)	Next-intl injects locale-specific translations and formatting on the client-side, after the page has been loaded.

When Nextjs renders your page on the server, it generates the initial HTML. However, when next-intl kicks in on the client-side, it re-renders the page with the translated content, effectively causing a second render. This means your page is being rendered twice: once on the server and again on the client.

The Solution: Unifying Rendering Modes

Now that we’ve identified the root cause, let’s explore ways to unify the rendering modes and avoid double rendering:

Method 1: Disable Server-Side Rendering (SSR)

One approach is to disable SSR for pages that use next-intl. This forces Nextjs to rely solely on CSR, ensuring that the page is only rendered once, on the client-side. To do this, add the following configuration to your `next.config.js` file:

module.exports = {
  // Disable SSR for pages using next-intl
  target: 'experimental-CSR',
};

This method comes with trade-offs, as it reduces the SEO benefits of SSR. However, it’s a viable solution if you prioritize client-side rendering.

Method 2: Use getStaticProps and getServerSideProps

Another approach is to leverage Nextjs’s built-in support for static site generation (SSG) and server-side rendering (SSR) using `getStaticProps` and `getServerSideProps`, respectively. These functions allow you to pre-render pages with locale-specific content, eliminating the need for CSR:

import { GetStaticProps, GetServerSideProps } from 'next';
import { useIntl } from 'next-intl';

// Example page component
const HomePage = () => {
  const intl = useIntl();

  return (
    <div>
      <h1>{intl.formatMessage({ id: 'title' })}</h1>
    </div>
  );
};

// Pre-render page with locale-specific content
export const getStaticProps: GetStaticProps = async ({ locale }) => {
  return {
    props: {
      intl: {
        locale,
        messages: await import(`../intl/${locale}.json`),
      },
    },
  };
};

// For non-static pages, use getServerSideProps
export const getServerSideProps: GetServerSideProps = async ({ locale }) => {
  return {
    props: {
      intl: {
        locale,
        messages: await import(`../intl/${locale}.json`),
      },
    },
  };
};

This method ensures that your page is rendered only once, either at build time or on the server, depending on your configuration.

Conclusion

In conclusion, the double rendering phenomenon when using Nextjs with next-intl is a common issue that can be addressed by understanding the rendering modes at play. By disabling SSR, using `getStaticProps` and `getServerSideProps`, or experimenting with other solutions, you can optimize your application for performance and readability. Remember, the key is to unify the rendering modes and eliminate unnecessary re-renders.

Bonus: Optimizing Performance with Nextjs and next-intl

As a bonus, here are some additional tips to optimize performance when using Nextjs with next-intl:

1. Use lazy loading: Defer loading of locale-specific content until it’s actually needed, reducing initial page load times.
2. Optimize images: Use image optimization techniques, such as lazy loading and compressing images, to reduce page weight.
3. Enable code splitting: Use Nextjs’s built-in code splitting feature to load only the necessary code for each page, reducing overall page size.
4. Use caching: Implement caching mechanisms, such as Redis or Memcached, to reduce the load on your server and improve response times.
5. Monitor performance: Use analytics tools, such as Web Vitals or Google PageSpeed Insights, to monitor performance and identify areas for improvement.

By following these best practices, you can ensure a fast, efficient, and SEO-friendly application that delights users worldwide!

The Final Word

In conclusion, the double rendering issue with Nextjs and next-intl is a solvable problem that requires a deep understanding of the rendering modes involved. By applying the solutions outlined in this article, you’ll be well on your way to creating a seamless internationalization experience for your users. Happy coding!

Here is the response:

Frequently Asked Question

Get answers to the most frequently asked questions about Nextjs with next-intl rendering the page twice!