5 Next.JS Tips You Never Heard About
Next.js is a powerful framework for building server-rendered React applications. It offers many features out of the box, such as automatic code splitting, static site generation, and server-side rendering. However, there are some advanced Next.js tips that aren’t talked about in mainstream guides. In this article, we’ll cover some of those tips that will take your app to the next level.
Use dynamic imports for third-party libraries
Next.js automatically code-splits your application, which means it only loads the code that’s needed for the current page. However, this doesn’t always work well for third-party libraries that aren’t built with code-splitting in mind.
To make sure that third-party libraries are also code-split, you can use dynamic imports. Dynamic imports allow you to load a module only when it’s needed, which can help reduce the initial bundle size of your application.
For example, instead of importing a third-party library like this:
import moment from 'moment';
You can use dynamic imports like this:
const moment = dynamic(() => import('moment'));
This will load the moment library only when it’s needed, which can help reduce the initial bundle size of your application.
Use a CDN for your static assets
Next.js automatically optimizes your images and other static assets, but it’s still important to serve them from a fast and reliable content delivery network (CDN).
You can use a CDN like Cloudflare or Amazon CloudFront to serve your static assets. This can help improve performance and reduce the load on your server.
To configure a CDN for your static assets, you can use the assetPrefix option in your next.config.js file:
module.exports = {
...
assetPrefix: 'https://yourcdn.com/',
...
};
This will prefix all your static asset URLs with the CDN URL.
Use server-side caching for expensive data operations
If your application has expensive data operations, such as complex database queries or API requests, it’s important to cache the results on the server side to improve performance.
Next.js provides a built-in cache API that you can use to cache data on the server side. The cache API is a simple key-value store that you can use to store and retrieve data.
For example, you can cache the results of a database query like this:
import { cache } from 'next/cache';
async function getPosts() {
const cachedPosts = await cache.get('posts');
if (cachedPosts) {
return cachedPosts;
}
const posts = await fetch('/api/posts');
await cache.set('posts', posts);
return posts;
}
This code checks if the results of the database query are already cached, and if so, returns them from the cache. Otherwise, it fetches the results from the database, caches them, and returns them.
By caching expensive data operations on the server side, you can reduce the load on your database and API servers, and improve the performance of your application.
Note: Be careful when caching sensitive data. A good rule of thumb is to cache only public data (not behind an authentication system).
Use ISR (Incremental Static Regeneration) for dynamic pages
Next.js provides a powerful feature called Incremental Static Regeneration (ISR) that allows you to generate static pages with dynamic content. This means that you can create pages that are both fast and dynamic, without sacrificing performance.
With ISR, you can generate a static version of a page, and then update that page at a later time with new data. For example, you can use ISR to generate a static blog post page with the initial content, and then update that page with new comments or other dynamic content as they come in.
To use ISR, you need to define a revalidate
option in your getStaticProps
function. This option specifies how often Next.js should regenerate the page with new data. Here’s an example:
export async function getStaticProps() {
const data = await fetch('https://example.com/api/data');
const posts = await data.json();
return {
props: {
posts
},
revalidate: 60 // regenerate the page every 60 seconds
}
}
In this example, the page will be regenerated every 60 seconds with new data from the API. This means that your users will always see the latest content, even if the page is static.
By using ISR, you can create fast and dynamic pages that are optimized for performance. This feature is particularly useful for content-heavy websites, such as blogs or news sites, where new content is added frequently.
Use a custom server to support WebSockets
Next.js provides a built-in server that’s suitable for most use cases. However, if you have advanced use cases like WebSockets or custom authentication, you may need to use a custom server.
You can use a custom server with Next.js by creating a server.js file at the root of your project. This file exports a function that creates an HTTP server and handles requests.
For example, here’s how you can create a custom server that handles WebSockets:
const http = require('http');
const WebSocket = require('ws');
const next = require('next');
const dev = process.env.NODE_ENV !== 'production';
const app = next({ dev });
const handle = app.getRequestHandler();
const server = http.createServer((req, res) => {
// handle HTTP requests
handle(req, res);
});
const wss = new WebSocket.Server({ server });
wss.on('connection', (ws) => {
// handle WebSocket connections
});
server.listen(3000, () => {
console.log('Ready on http://localhost:3000');
});
This creates an HTTP server and a WebSocket server that listens on port 3000.
Note: Using a custom server opts you out of automatic static optimization, and essentially prevents you from deploying to Vercel.
In conclusion, by using advanced Next.js features like ISR, you can create fast and scalable web applications that are optimized for performance. These tips can help you take your Next.js application to the next level, and provide your users with an optimal experience.
That’s all for now folks. As always, if you have any questions, feel free to reach out or post a reply here. Have a lovely day!