What Is Next.js? A Modern Web Framework Guide

You want to build a web application with React, but don't want to deal with SEO, performance, and routing. Next.js steps in right here — a production-ready framework built on top of React.

What Is Next.js?

Next.js is a full-stack web framework developed by Vercel, built on React. It takes React's powerful component system and adds routing, server-side rendering, static site generation, and API development capabilities on top.

Why Next.js?

React Alone Isn't Enough

React is a UI library — not a complete framework. When working with React, you need to solve these yourself:

• Routing (page navigation)
• SEO (server-side rendering)
• Code splitting (performance)
• API endpoints
• Build optimization

Next.js provides all of these out of the box.

Core Next.js Features

1. File-Based Routing

Folder structure = URL structure:

app/
├── page.tsx          → /
├── about/
│   └── page.tsx      → /about
├── blog/
│   ├── page.tsx      → /blog
│   └── [slug]/
│       └── page.tsx  → /blog/post-1

2. Rendering Strategies

SSR (Server-Side Rendering): Rendered on the server with each request. Ideal for SEO and dynamic content.

SSG (Static Site Generation): HTML generated at build time. Ideal for blogs, documentation.

ISR (Incremental Static Regeneration): Static pages updated at set intervals. Best performance + freshness balance.

CSR (Client-Side Rendering): Rendered in the browser. Suitable for dashboards.

3. Server Components

With React Server Components:

• Smaller JavaScript bundle
• Data fetching on the server
• Faster page loading
• Keeping sensitive data off the client

4. API Routes

Write backend APIs inside Next.js:

// app/api/users/route.ts
export async function GET() {
  const users = await db.user.findMany();
  return Response.json(users);
}

5. Automatic Optimizations

• Image Optimization — Auto lazy loading, WebP/AVIF
• Font Optimization — Google Fonts auto self-hosting
• Script Optimization — Controlled third-party script loading
• Code Splitting — Automatic per-page splitting

Next.js vs Other Frameworks

| Feature | Next.js | Nuxt.js | Remix | Astro | |---------|---------|---------|-------|-------| | Base | React | Vue | React | Agnostic | | SSR | ✅ | ✅ | ✅ | ✅ | | SSG | ✅ | ✅ | ❌ | ✅ | | API Routes | ✅ | ✅ | ✅ | ✅ | | Edge Runtime | ✅ | ✅ | ✅ | ❌ | | Popularity | Highest | High | Growing | Growing | | Learning curve | Medium | Medium | Medium | Low |

What Can You Build with Next.js?

• Corporate websites — SEO, performance, multilingual
• E-commerce — Product pages, cart, checkout
• Blog/media — MDX support, static generation
• Dashboards — Full-stack, API integration
• SaaS applications — Auth, database, API
• Portfolio sites — Fast, SEO-friendly

Who Uses Next.js?

• Netflix — Membership pages
• TikTok — Web application
• Twitch — Stream pages
• Nike — E-commerce
• Hulu — Streaming platform

Getting Started

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

Conclusion

Next.js is the standard web development framework in 2026. If you know React, switching to Next.js is easy — and it gives you the power to create production-ready, performant, SEO-friendly applications.

If you'd like to build professional web applications with Next.js, get in touch: info@cagribilgehan.com. Check out my projects: cagribilgehan.com