Learn the Next.js App Router

Introduction

The App Router is a powerful new feature introduced in Next.js 13 that provides an intuitive and flexible way to handle routing in your Next.js applications [^1]. This guide will walk you through the basics of using the App Router and highlight some of its key features.

Getting Started

To start using the App Router, you need to create a new Next.js project or update an existing one to version 13 or later. The App Router works alongside the existing Pages Router, allowing for incremental adoption [^1].

Creating a New Project

To create a new Next.js project with the App Router:

npx create-next-app@latest my-app --use-app-router
cd my-app

File-Based Routing

The App Router uses a file-system based routing mechanism. Here's how it works:

  1. Create a new app directory in your project root.
  2. Inside the app directory, create folders and files that correspond to your desired route structure.

For example:

app/
├── page.tsx
├── about/
│ └── page.tsx
└── blog/
├── page.tsx
└── [slug]/
└── page.tsx

In this structure:

  • / is handled by app/page.tsx
  • /about is handled by app/about/page.tsx
  • /blog is handled by app/blog/page.tsx
  • /blog/[slug] is handled by app/blog/[slug]/page.tsx

Key Features

1. Layouts

Layouts allow you to share UI between multiple pages. Create a layout.tsx file in a folder to define a layout for all pages in that folder and its subfolders [^1].

// app/layout.tsx
export default function RootLayout({ children }) {
return (
<html lang="en">
<body>{children}</body>
</html>
)
}

2. Server Components

By default, components inside the app directory are React Server Components. This allows for better performance and easier server-side rendering [^1].

3. Data Fetching

The App Router provides new ways to fetch data, including the use of async/await in Server Components:

// app/page.tsx
async function getData() {
const res = await fetch('https://api.example.com/data')
return res.json()
}

export default async function Page() {
const data = await getData()
return <main>{/* Use data */}</main>
}

4. Loading UI and Streaming

You can create loading states for your routes by adding a loading.tsx file:

// app/loading.tsx
export default function Loading() {
return <p>Loading...</p>
}

Conclusion

The App Router in Next.js provides a powerful and flexible way to handle routing in your applications. With features like nested layouts, server components, and improved data fetching, it offers a great developer experience and performance benefits.

For more detailed information, check out the official Next.js documentation.


This guide provides a basic overview of using the App Router in Next.js. Remember that the App Router is designed to work alongside the existing Pages Router, allowing for gradual adoption in your projects [^1].
← Return home