Next.js 15.5: Key Features, Updates, What Developers Need to Know


Never miss an update
Subscribe to receive news and special offers.
By subscribing you agree to our Privacy Policy.
I was midway through a project—juggling client-side routes, middleware quirks, and build times that felt like watching paint dry.
Then version 15.5 dropped, and I thought:
"okay, they might’ve actually read my mind."
Turns out, they did.
Here’s what stood out to me, straight from the official release:
next build --turbopack now works for production, already serving over 1.2B requests on nextjs.org.fs, crypto, and npm packages in your middleware.PageProps/LayoutProps, plus a new next typegen command.next lint is deprecated — moving forward, set up ESLint or Biome manually. next lint disappears in v16.legacyBehavior, AMP, Image quality config, and local image patterns.I ran a next build --turbopack. Still not instant, but noticeably faster. Some projects already report 2–5× speed improvements. That’s time saved on every deployment.
Need to tap into the filesystem or generate crypto-secure tokens before a page renders? Now you can. Middleware runs in a full Node.js runtime—stability unlocked.
// middleware.ts
import { NextRequest, NextResponse } from 'next/server';
export const config = {
runtime: 'nodejs', // Now stable!
};
export function middleware(request: NextRequest) {
// Access to full Node.js APIs and npm packages
const fs = require('fs');
const crypto = require('crypto');
// Complex authentication logic
const token = request.headers.get('authorization');
if (!isValidToken(token)) {
return NextResponse.redirect(new URL('/login', request.url));
}
return NextResponse.next();
}
function isValidToken(token: string | null): boolean {
// Use Node.js crypto for validation
// Access file system, databases, etc.
return true;
}Typed routes now work with both Webpack and Turbopack. Example: if you mistype <Link href="/dashboard">, the compiler warns before you hit save. next typegen also helps validate routes during CI.
// next.config.ts
const nextConfig = {
typedRoutes: true, // Now stable!
// Other code
};
export default nextConfig;No more upgrade-day headaches. You’ll see dev warnings for deprecated features so you can fix them before v16 ships.
I refactored a project with type-safe links and middleware that authenticates users using crypto-hashed tokens stored in a file.
It felt natural—not a hack. And I caught a broken route before it hit staging. Small wins that add up.
--turbopack for faster builds.next.config.ts.next lint).If you enjoy updates like these—free of hype, heavy on developer value—my newsletter breaks them down in plain English. Subscribe and stay ready for what’s next in React and Next.js.
For more informations, go to the official doc Next.js 15.5