What is Next.js 15?
Next.js is an open-source web framework built on top of Facebook's React library, developed by Vercel. Released in 2016, it has since grown to over 130,000 GitHub stars, making it one of the most popular web frameworks in the world.
📊 2026 Statistics:
- Weekly npm downloads: 30 million+
- GitHub stars: 130,000+
- Used by: TikTok, Twitch, Nike, GitHub, Notion, Hulu
- Stack Overflow Survey 2025: Most used web framework
Vanilla React vs Next.js
React is a UI library — it only handles the View layer. Routing, SEO, data fetching require additional libraries. Next.js solves these out of the box:
| Feature | React (CRA/Vite) | Next.js 15 |
|---|---|---|
| Routing | Requires React Router | Built-in App Router |
| SEO | Hard (CSR) | Easy (SSR/SSG) |
| Data Fetching | useEffect + fetch | async Server Components |
| API Endpoints | Separate backend needed | Route Handlers built in |
| Image Optimisation | Manual | next/image automatic |
| Performance | Medium | High (Turbopack) |
Next.js 15 Key Features
- Turbopack (stable): Rust-based bundler replacing Webpack. 90% faster in dev mode
- React 19 support: use() hook, Actions, optimistic updates
- Improved caching: fetch requests are no longer cached by default (more predictable)
- After() API: Run tasks in the background after the response is sent
- Form component: Dedicated component for HTML form management
When to Use Next.js
- ✅ Projects where SEO matters (blog, e-commerce, landing pages)
- ✅ Full-stack apps (frontend + API in one repo)
- ✅ Performance-critical apps (Core Web Vitals)
- ✅ Large-scale enterprise projects
- ❌ Internal admin panels only (SEO irrelevant)
- ❌ Mobile apps (use React Native instead)
Önemli Noktalar
- Next.js is a full-stack framework built on React
- 30M+ weekly npm downloads — industry leader
- App Router, Server Components and Turbopack are the headline features
- Ideal for SEO-critical and performance-demanding projects