Published: 25 Januar 2023
Introduction
Next.js has become the go-to React framework for building modern applications. With the release of Next.js 13 and 14, the framework has taken a significant leap forward, introducing the App Router, React Server Components, improved caching, and better performance optimizations.
This article will cover:
- The biggest changes in Next.js 13 & 14
- How the App Router replaces the Pages Router
- Why these updates matter for your projects
1. The App Router: A Major Shift in Next.js
In Next.js 13, the App Router (app/) was introduced alongside the existing Pages Router (pages/). However, with Next.js 14, the App Router has become the default and is now recommended for all new projects.
How the App Router Changes Routing
✅ Uses React Server Components (RSC) by default – No unnecessary client-side JavaScript.
✅ File-based routing with nested layouts – Simplifies UI structure.
✅ Automatic static and dynamic rendering – No need for getStaticProps or getServerSideProps.
✅ Built-in Suspense and Streaming – Faster page loads and improved user experience.
🚀 Example: A simple route in the App Router:
// app/page.tsx (Replaces pages/index.tsx)
export default function Home() {
return <h1>Welcome to Next.js 14!</h1>;
}
Instead of defining API routes in pages/api/, you now use server functions inside the App Router:
// app/api/hello/route.ts
export async function GET() {
return Response.json({ message: "Hello from Next.js 14!" });
}
2. Pages Router vs. App Router: What’s Different?
| Feature | Pages Router (pages/) | App Router (app/) |
|---|---|---|
| File-based routing | ✅ Yes | ✅ Yes |
| Uses React Server Components | ❌ No | ✅ Yes (default) |
getStaticProps / getServerSideProps | ✅ Yes | ❌ No (Replaced by fetch()) |
| Server Actions (mutations on the server) | ❌ No | ✅ Yes |
| Nested Layouts | ❌ No | ✅ Yes |
| API Routes | ✅ Yes (pages/api/) | ✅ Yes (app/api/) |
| Streaming & Suspense | ❌ No | ✅ Yes |
Should you migrate? If you’re starting a new project, use the App Router. For existing projects, migration depends on your needs, as the Pages Router is still supported.
3. Layouts & Nested Routing: A Game-Changer
The biggest improvement in the App Router is the way layouts work. Instead of manually wrapping pages with layout components, you can now define them once at the folder level.
🚀 Example: A shared layout for a dashboard:
// app/dashboard/layout.tsx
export default function DashboardLayout({ children }: { children: React.ReactNode }) {
return (
<div>
<nav>Sidebar</nav>
<main>{children}</main>
</div>
);
}
This layout automatically wraps all pages inside /dashboard/, reducing code duplication.
4. Server Components & Server Actions: Less JavaScript, Faster Apps
With Next.js 14, React Server Components (RSC) are now default, meaning components don’t ship unnecessary JavaScript to the client.
🚀 Example: Fetching data directly inside a component (without useEffect() or API calls).
// app/products/page.tsx
async function getProducts() {
const res = await fetch("https://api.example.com/products");
return res.json();
}
export default async function Products() {
const products = await getProducts();
return (
<ul>
{products.map((p) => (
<li key={p.id}>{p.name}</li>
))}
</ul>
);
}
Why is this better?
✅ No extra API requests – Fetching happens on the server.
✅ Better SEO – Content is ready when the page loads.
✅ Smaller JavaScript bundles – Less client-side code means faster performance.
Server Actions: Mutations Without API Routes
Previously, handling form submissions required API routes. With Server Actions, you can now handle backend logic directly inside your component.
🚀 Example: A form that submits data without an API route.
// app/contact/page.tsx
"use server"; // Runs only on the server
async function sendMessage(formData: FormData) {
const message = formData.get("message");
console.log("Received:", message);
}
export default function ContactForm() {
return (
<form action={sendMessage}>
<input name="message" placeholder="Type a message" required />
<button type="submit">Send</button>
</form>
);
}
🚀 Benefits:
- No API routes needed
- Less boilerplate
- Secure – No client-side exposure
5. Middleware & Edge Functions: Faster Global Processing
Next.js Middleware lets you process requests before they hit a route, improving personalization, security, and performance.
🚀 Example: Redirecting users based on authentication.
// middleware.ts
import { NextResponse } from "next/server";
export function middleware(req) {
const token = req.cookies.get("auth");
if (!token) return NextResponse.redirect("/login");
}
✅ Runs globally before rendering.
✅ Fast – Processes requests at the Edge.
6. Performance Improvements in Next.js 14
🔹 New next/image features – Faster image loading with automatic optimizations.
🔹 Partial Prerendering (Experimental) – Combines static and dynamic rendering for faster pages.
🔹 Faster Link Preloading – Next.js automatically preloads links for instant navigation.
🔹 Streaming by default – Pages load progressively instead of waiting for all data.
7. Should You Upgrade to Next.js 14?
✅ If you’re starting a new project → Use Next.js 14 with the App Router.
✅ If you have an existing Next.js 12/13 project → Consider migrating gradually.
✅ If you rely on getServerSideProps or getStaticProps → You may need to rewrite some logic.
How to Upgrade
- Update your Next.js version
npm install next@latest react@latest react-dom@latest - Move pages to the
app/directory (optional). - Refactor data fetching using Server Components.
Final Thoughts: Next.js 14 is a Big Step Forward
Next.js 14 solidifies the App Router as the future of React applications. By embracing React Server Components, Server Actions, and streaming, developers can now build faster, more scalable applications with less effort.
💡 Key Takeaways:
- App Router replaces Pages Router for better flexibility and performance.
- React Server Components are now the default, reducing JavaScript bloat.
- Server Actions simplify mutations without API routes.
- Performance improvements make apps load faster with streaming and optimizations.
Next.js is evolving, and now is the best time to start using these new features in your projects. 🚀
