Next.js React Framework

Next.js is a free and open-source React framework for building production-grade web applications, created by Guillermo Rauch (CEO of Vercel, formerly ZEIT) and the Vercel team in October 2016. Next.js is one of the most popular React frameworks, used by TikTok, Netflix, Hulu, Twitch, Notion, and many other major companies. Key features: file-based routing: pages and routes are defined by the file system structure in the app/ (App Router, Next.js 13+) or pages/ (Pages Router) directory. Each file becomes a route, and dynamic routes use [param] brackets. Nested layouts are supported. Server-side rendering (SSR): pages can be rendered on the server on each request, providing fresh data and SEO benefits. The server renders the HTML and sends it to the client, which then hydrates. Static site generation (SSG): pages can be pre-rendered at build time, generating static HTML files for maximum performance. Incremental Static Regeneration (ISR) updates static pages in the background without rebuilding the entire site. React Server Components (RSC): Next.js 13 introduced the App Router with Server Components as the default. Server Components render on the server, reducing the JavaScript bundle size and enabling direct database access. Streaming: pages stream HTML as it becomes available, improving perceived performance. API routes: create backend API endpoints within the same project (app/api/ or pages/api/), handling HTTP requests, database queries, and authentication. Optimization components: next/image for automatic image optimization (resize, format conversion to WebP/AVIF, lazy loading), next/font for font optimization, next/script for optimized script loading. Middleware: run code before a request completes, enabling authentication, redirects, A/B testing, and localization. Internationalization (i18n). TypeScript first-class. Edge runtime. JavaScript/TypeScript. MIT.