SSR (Server-Side Rendering) trong Next.js là gì?

SSR render HTML trên server cho mỗi request, trả về fully-rendered HTML cho browser. Tốt cho: SEO, trang có data thay đổi thường xuyên theo user, first paint nhanh. Trong App Router: mặc định Server Components là SSR. Pages Router: dùng getServerSideProps.

Nhược điểm: server phải xử lý nhiều, TTFB cao hơn SSG.

SSR renders HTML on the server for every request and delivers fully-rendered HTML to the browser.

• It is great for: SEO, pages with frequently changing per-user data, and fast first paint.
• In the App Router, Server Components are SSR by default.
• In the Pages Router, use getServerSideProps.
• Downsides: higher server load and higher TTFB compared to SSG.