Getting Started with Next.js 15

Welcome to this comprehensive guide on building modern web applications with Next.js 15!

What is Next.js?

Next.js is a powerful React framework that enables you to build production-ready applications with ease. Version 15 brings exciting new features and improvements including the stable App Router, Server Actions, and enhanced performance.

Setting Up Your Project

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

Key Features in Next.js 15

Server Components

Server Components are the default in Next.js 15. They render on the server and send HTML to the client, resulting in smaller JavaScript bundles and faster page loads.

// This is a Server Component by default
export default async function Page() {
  const data = await fetch('https://api.example.com/data')
  const posts = await data.json()

  return (
    <main>
      {posts.map(post => (
        <article key={post.id}>
          <h2>{post.title}</h2>
          <p>{post.excerpt}</p>
        </article>
      ))}
    </main>
  )
}

App Router

The App Router uses file-system based routing with support for layouts, nested routes, loading states, and error handling.

Server Actions

Server Actions allow you to define server-side functions that can be called directly from your components, eliminating the need for separate API routes in many cases.

'use server'

export async function createPost(formData: FormData) {
  const title = formData.get('title')
  const content = formData.get('content')

  await db.insert(posts).values({ title, content })
  revalidatePath('/blog')
}

Image Optimization

Next.js automatically optimizes images with the next/image component, providing lazy loading, responsive sizing, and modern formats like WebP.

Font Optimization

The next/font module automatically optimizes web fonts, eliminating layout shifts and improving performance.

Building Your First Page

Create a new page in app/page.tsx:

export default function Home() {
  return (
    <main className="container mx-auto px-4 py-8">
      <h1 className="text-4xl font-bold">Welcome to Next.js 15!</h1>
      <p className="mt-4 text-lg text-gray-600">
        Build amazing web applications with the latest features.
      </p>
    </main>
  )
}

Performance Improvements

Next.js 15 includes significant performance improvements:

• Turbopack for faster development builds
• Partial Prerendering for optimal loading strategies
• Improved caching with more granular control

Conclusion

Next.js 15 with TypeScript provides an excellent developer experience and production-ready performance. The combination of Server Components, Server Actions, and the App Router makes it the go-to framework for modern React applications. Start building today!