Summary notes for Next.js

Objectives: Complete Next.js Summary Notes

Complete Next.js Notes

NEXT.JS FULL NOTES (Beginner to Advanced)

1. Introduction to Next.js

Next.js is a React framework used to build fast, scalable, SEO-friendly, and production-ready web applications.

Why Next.js?

  • Built on top of React
  • Server-Side Rendering (SSR)
  • Static Site Generation (SSG)
  • File-based routing
  • Built-in backend using API routes
  • Automatic performance optimization

2. Prerequisites

  • HTML
  • CSS
  • JavaScript (ES6)
  • Basic React knowledge

3. Installing Next.js

Requirements: Node.js version 18 or higher.

npx create-next-app@latest my-app
cd my-app
npm run dev

Open in browser:

http://localhost:3000

4. Project Structure

my-app/
 ├── app/
 │   ├── page.js
 │   ├── layout.js
 │   ├── globals.css
 ├── public/
 ├── package.json
  • page.js – Page UI
  • layout.js – Shared layout
  • globals.css – Global styles
  • public – Static assets

5. Routing in Next.js (App Router)

Next.js uses file-based routing.

app/page.js        → /
app/about/page.js  → /about
app/blog/page.js   → /blog

Dynamic Routing

app/blog/[id]/page.js → /blog/1

6. Layouts

Layouts wrap pages and persist across navigation.

export default function RootLayout({ children }) {
  return (
    <html>
      <body>
        {children}
      </body>
    </html>
  )
}

7. Navigation

Using Link

import Link from 'next/link'

<Link href="/about">About</Link>

Using useRouter

'use client'
import { useRouter } from 'next/navigation'

const router = useRouter()
router.push('/login')

8. Server vs Client Components

Server Components

  • Default in Next.js
  • Faster
  • More secure

Client Components

  • Use state and effects
  • Require 'use client'

9. Styling in Next.js

  • Global CSS
  • CSS Modules
  • Tailwind CSS

10. Image Optimization

import Image from 'next/image'

<Image src="/hero.png" width={400} height={300} alt="Hero" />

11. SEO and Metadata

export const metadata = {
  title: 'Home',
  description: 'Welcome to Next.js'
}

12. Data Fetching

Next.js supports:

  • Static Site Generation (SSG)
  • Server-Side Rendering (SSR)
  • Client-side fetching

13. API Routes

app/api/users/route.js

export async function GET() {
  return Response.json({ users: [] })
}

14. Forms & Server Actions

'use server'
export async function createUser(formData) {
  // handle form
}

15. Authentication

  • NextAuth.js
  • Clerk
  • Firebase Authentication

16. Environment Variables

.env.local
NEXT_PUBLIC_API_URL=http://example.com

17. Middleware

export function middleware(request) {
  // auth, redirects
}

18. Deployment

Recommended platform: Vercel

npm run build

19. Performance Optimization

  • Image optimization
  • Code splitting
  • Caching
  • Server components

20. Summary

Next.js is a powerful React framework that combines frontend and backend features, improves performance, and simplifies deployment for modern web applications.

Reference Book: N/A

Author name: MWALA_LEARN Work email: biasharabora12@gmail.com
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