React Server Components: a practical guide for fullstack developers

React Server Components represent a fundamental shift in how React applications render. Components can run on the server, sending only the HTML result to the client. This reduces the JavaScript bundle size, improves initial load time, and gives server-side data access without APIs.

Server Components are the default in Next.js App Router. They run exclusively on the server, have direct access to databases and file systems, and send only rendered HTML to the client. They cannot use hooks, event handlers, or browser APIs.

Client Components are the traditional React components that run in the browser. They handle interactivity, use hooks, and respond to user input. Mark a component with 'use client' to make it a Client Component.

The best architecture starts with Server Components by default. Make every component a Server Component unless it needs interactivity. This minimizes the JavaScript sent to the client. Extract Client Components only for interactive parts of your UI.

Data fetching is simpler with Server Components. Fetch data directly in the component instead of in a useEffect. The component renders on the server with all the data it needs. There's no loading state, no waterfall requests.

Server Components work well with streaming. The server can stream HTML to the client as it becomes available. The page starts rendering immediately while slower data fetches complete. This creates a faster perceived load time.

Adopt Server Components incrementally. You don't need to rewrite your entire application. Start with data-heavy pages where Server Components provide the most benefit. Use the App Router for new pages while keeping existing pages in the Pages Router.

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Rizwan Saleem | https://rizwansaleem.co