Next.js 12: Elevating the React Ecosystem

Optimized Performance with Rust Compiler

Next.js 12 takes performance optimization to the next level by replacing the Babel compiler with an extensible Rust compiler, SWC. This results in:

• 3 times faster refresh locally
• 5 times faster builds for production

This means faster build times on production and instant feedback in local development, leading to a better developer experience and faster development time.

npx next build --rust-compiler

The Power of Middlewares

Middlewares in Next 12 enable developers to use code over configuration, allowing them to:

• Run code before a request is completed
• Modify the response by rewriting, redirecting, adding headers, and more

With middleware, developers can implement features like:

• Authentication
• Bot protection
• Redirects and rewrites
• Server-side analytics
• Logging
• Handling unsupported browsers

// Example middleware function
export default async function middleware(req, res) {
  // Run code before a request is completed
  // Modify the response as needed
}

React 18 Support

Next 12 introduces experimental support for React 18, including:

• Server-side Suspense
• Automatic patching of updates

This allows developers to take advantage of React 18’s features, such as:

• Server-side rendering using HTTP streaming
• React Server Components, which enable native rendering of HTML from a React component on the server

// Example React 18 component
import { Suspense } from 'eact';

function MyComponent() {
  return (
    Loading...}>
      {/* Your component code here */}
    
  );
}

ES Module Support and URL Import

Next 12 prioritizes ES modules over CommonJS, making it easier for developers to adopt ES modules incrementally. Additionally, Next 12 experimentally supports URL imports of packages that use ES modules, allowing developers to:

• Import packages directly from a URL without installation or separate build steps

// Example URL import
import package from 'https://example.com/package.mjs';

Bot-Aware ISR Fallback and Smaller Images

Other notable features in Next 12 include:

• Bot-Aware ISR fallback, which automatically server-renders ISR pages for web crawlers
• Support for AVIF images, which enables 20 percent smaller images compared to WebP

Output File Tracing and More

Finally, Next 12 improves output file tracing by bringing Vercel’s @verce/nft package to Next.js 12, allowing integrators to automatically leverage the traces Next provides.

npx next trace

With its plethora of exciting features, Next 12 is set to revolutionize the way we build React applications. Although some features are still experimental, developers can opt-in and start using them today. As React 18 moves towards a stable release, Next 12 is poised to become an essential tool in every React developer’s toolkit.