Getting Started with Next.js 14: A Complete Guide

Next.js 14 introduces several game-changing features that make building modern web applications faster and more efficient than ever. In this comprehensive guide, we'll explore the new App Router, Server Components, and advanced optimization techniques.

What's New in Next.js 14

Next.js 14 brings significant improvements to developer experience and application performance:

Turbopack: The new Rust-based bundler that's up to 53% faster than Webpack
Server Actions: Full-stack React architecture for seamless client-server integration
Partial Prerendering: Experimental feature combining static and dynamic rendering
Improved TypeScript Support: Better type safety and developer experience

Setting Up Your First Next.js 14 Project

Let's start by creating a new Next.js project with TypeScript and Tailwind CSS:

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

This command creates a new project with the App Router enabled by default, which is the recommended approach for new applications.

Understanding the App Router

The App Router is built on React's Server Components and introduces a new file-system based routing structure:

app/
├── layout.tsx          # Root layout
├── page.tsx           # Home page
├── globals.css        # Global styles
├── about/
│   └── page.tsx       # About page
└── blog/
    ├── page.tsx       # Blog listing
    └── [slug]/
        └── page.tsx   # Dynamic blog post

Creating Layouts

Layouts are shared UI components that wrap multiple pages:

// app/layout.tsx
export default function RootLayout({
  children,
}: {
  children: React.ReactNode
}) {
  return (
    <html lang="en">
      <body>
        <nav>
          <a href="/">Home</a>
          <a href="/about">About</a>
          <a href="/blog">Blog</a>
        </nav>
        <main>{children}</main>
      </body>
    </html>
  )
}

Server Components vs Client Components

Next.js 14 renders components on the server by default, providing better performance and SEO:

Server Components (Default)

// This component runs on the server
async function ServerComponent() {
  const data = await fetch('https://api.example.com/data')
  const posts = await data.json()
  
  return (
    <div>
      {posts.map(post => (
        <div key={post.id}>{post.title}</div>
      ))}
    </div>
  )
}

Client Components

'use client'

// This component runs in the browser
import { useState } from 'react'

function ClientComponent() {
  const [count, setCount] = useState(0)
  
  return (
    <button onClick={() => setCount(count + 1)}>
      Count: {count}
    </button>
  )
}

Advanced Features

Server Actions

Server Actions enable you to run server-side code directly from client components:

// app/actions.ts
'use server'

export async function createPost(formData: FormData) {
  const title = formData.get('title')
  const content = formData.get('content')
  
  // Save to database
  await db.posts.create({ title, content })
  
  redirect('/blog')
}

// app/create-post/page.tsx
import { createPost } from '../actions'

export default function CreatePost() {
  return (
    <form action={createPost}>
      <input name="title" placeholder="Post title" />
      <textarea name="content" placeholder="Post content" />
      <button type="submit">Create Post</button>
    </form>
  )
}

Streaming and Suspense

Improve user experience with streaming and React Suspense:

import { Suspense } from 'react'

function LoadingSkeleton() {
  return <div className="animate-pulse bg-gray-200 h-4 rounded" />
}

async function SlowComponent() {
  // Simulate slow data fetch
  await new Promise(resolve => setTimeout(resolve, 2000))
  return <div>Data loaded!</div>
}

export default function Page() {
  return (
    <div>
      <h1>My Page</h1>
      <Suspense fallback={<LoadingSkeleton />}>
        <SlowComponent />
      </Suspense>
    </div>
  )
}

Performance Optimization

Image Optimization

Use the Next.js Image component for automatic optimization:

import Image from 'next/image'

export default function Gallery() {
  return (
    <Image
      src="/hero.jpg"
      alt="Hero image"
      width={800}
      height={400}
      priority
      className="rounded-lg"
    />
  )
}

Font Optimization

Load fonts efficiently with next/font:

// app/layout.tsx
import { Inter, Roboto_Mono } from 'next/font/google'

const inter = Inter({
  subsets: ['latin'],
  variable: '--font-inter',
})

const roboto_mono = Roboto_Mono({
  subsets: ['latin'],
  variable: '--font-roboto-mono',
})

export default function RootLayout({
  children,
}: {
  children: React.ReactNode
}) {
  return (
    <html lang="en" className={`${inter.variable} ${roboto_mono.variable}`}>
      <body className="font-inter">{children}</body>
    </html>
  )
}

Best Practices

Use Server Components by default: Only add 'use client' when necessary
Optimize images: Always use the Image component for better performance
Implement proper loading states: Use Suspense for better UX
Type everything: Leverage TypeScript for better developer experience
Follow the colocation principle: Keep related files close together

Conclusion

Next.js 14 represents a significant leap forward in React-based web development. The combination of Server Components, the App Router, and performance optimizations makes it easier than ever to build fast, modern web applications.

Start experimenting with these features in your next project, and you'll quickly see the benefits in both developer experience and application performance.

Have questions about Next.js 14? Feel free to reach out on Twitter or check out the official documentation.

Getting Started with Next.js 14: A Complete Guide

What's New in Next.js 14

Next.js 14 brings significant improvements to developer experience and application performance:

Turbopack: The new Rust-based bundler that's up to 53% faster than Webpack
Server Actions: Full-stack React architecture for seamless client-server integration
Partial Prerendering: Experimental feature combining static and dynamic rendering
Improved TypeScript Support: Better type safety and developer experience

Setting Up Your First Next.js 14 Project

Let's start by creating a new Next.js project with TypeScript and Tailwind CSS:

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

This command creates a new project with the App Router enabled by default, which is the recommended approach for new applications.

Understanding the App Router

The App Router is built on React's Server Components and introduces a new file-system based routing structure:

app/
├── layout.tsx          # Root layout
├── page.tsx           # Home page
├── globals.css        # Global styles
├── about/
│   └── page.tsx       # About page
└── blog/
    ├── page.tsx       # Blog listing
    └── [slug]/
        └── page.tsx   # Dynamic blog post

Creating Layouts

Layouts are shared UI components that wrap multiple pages:

// app/layout.tsx
export default function RootLayout({
  children,
}: {
  children: React.ReactNode
}) {
  return (
    <html lang="en">
      <body>
        <nav>
          <a href="/">Home</a>
          <a href="/about">About</a>
          <a href="/blog">Blog</a>
        </nav>
        <main>{children}</main>
      </body>
    </html>
  )
}

Server Components vs Client Components

Next.js 14 renders components on the server by default, providing better performance and SEO:

Server Components (Default)

// This component runs on the server
async function ServerComponent() {
  const data = await fetch('https://api.example.com/data')
  const posts = await data.json()
  
  return (
    <div>
      {posts.map(post => (
        <div key={post.id}>{post.title}</div>
      ))}
    </div>
  )
}

Client Components

'use client'

// This component runs in the browser
import { useState } from 'react'

function ClientComponent() {
  const [count, setCount] = useState(0)
  
  return (
    <button onClick={() => setCount(count + 1)}>
      Count: {count}
    </button>
  )
}

Advanced Features

Server Actions

Server Actions enable you to run server-side code directly from client components:

// app/actions.ts
'use server'

export async function createPost(formData: FormData) {
  const title = formData.get('title')
  const content = formData.get('content')
  
  // Save to database
  await db.posts.create({ title, content })
  
  redirect('/blog')
}

// app/create-post/page.tsx
import { createPost } from '../actions'

export default function CreatePost() {
  return (
    <form action={createPost}>
      <input name="title" placeholder="Post title" />
      <textarea name="content" placeholder="Post content" />
      <button type="submit">Create Post</button>
    </form>
  )
}

Streaming and Suspense

Improve user experience with streaming and React Suspense:

import { Suspense } from 'react'

function LoadingSkeleton() {
  return <div className="animate-pulse bg-gray-200 h-4 rounded" />
}

async function SlowComponent() {
  // Simulate slow data fetch
  await new Promise(resolve => setTimeout(resolve, 2000))
  return <div>Data loaded!</div>
}

export default function Page() {
  return (
    <div>
      <h1>My Page</h1>
      <Suspense fallback={<LoadingSkeleton />}>
        <SlowComponent />
      </Suspense>
    </div>
  )
}

Performance Optimization

Image Optimization

Use the Next.js Image component for automatic optimization:

import Image from 'next/image'

export default function Gallery() {
  return (
    <Image
      src="/hero.jpg"
      alt="Hero image"
      width={800}
      height={400}
      priority
      className="rounded-lg"
    />
  )
}

Font Optimization

Load fonts efficiently with next/font:

// app/layout.tsx
import { Inter, Roboto_Mono } from 'next/font/google'

const inter = Inter({
  subsets: ['latin'],
  variable: '--font-inter',
})

const roboto_mono = Roboto_Mono({
  subsets: ['latin'],
  variable: '--font-roboto-mono',
})

export default function RootLayout({
  children,
}: {
  children: React.ReactNode
}) {
  return (
    <html lang="en" className={`${inter.variable} ${roboto_mono.variable}`}>
      <body className="font-inter">{children}</body>
    </html>
  )
}

Best Practices

Use Server Components by default: Only add 'use client' when necessary
Optimize images: Always use the Image component for better performance
Implement proper loading states: Use Suspense for better UX
Type everything: Leverage TypeScript for better developer experience
Follow the colocation principle: Keep related files close together

Conclusion

Start experimenting with these features in your next project, and you'll quickly see the benefits in both developer experience and application performance.

Have questions about Next.js 14? Feel free to reach out on Twitter or check out the official documentation.

Getting Started with Next.js 14: A Complete Guide

Getting Started with Next.js 14: A Complete Guide

What's New in Next.js 14

Setting Up Your First Next.js 14 Project

Understanding the App Router

Creating Layouts

Server Components vs Client Components

Server Components (Default)

Client Components

Advanced Features

Server Actions

Streaming and Suspense

Performance Optimization

Image Optimization

Font Optimization

Best Practices

Conclusion

Meisam Ahmadi

Getting Started with Next.js 14: A Complete Guide

Getting Started with Next.js 14: A Complete Guide

What's New in Next.js 14

Setting Up Your First Next.js 14 Project

Understanding the App Router

Creating Layouts

Server Components vs Client Components

Server Components (Default)

Client Components

Advanced Features

Server Actions

Streaming and Suspense

Performance Optimization

Image Optimization

Font Optimization

Best Practices

Conclusion

Meisam Ahmadi