SSR

Server-Side Rendering generates the HTML for a page on the server each time a user requests it. Unlike SPAs, the browser receives a fully rendered page, which improves initial load time and SEO. Next.js uses SSR by default for dynamic routes, combining the speed of traditional web pages with the interactivity of modern JavaScript frameworks.

If static generation is a printed brochure, SSR is a chef cooking each plate to order. When a visitor requests a page, the server assembles it fresh — pulling their account details, current stock levels, or today's prices — and sends back a finished page. The visitor sees real content immediately, not a blank screen waiting for JavaScript to fetch data.

Why it matters for your project: SSR earns its keep whenever pages must be both dynamic and publicly visible. An e-commerce product page needs live pricing and stock and needs to rank on Google — SSR delivers both. A personalized dashboard needs fresh per-user data on first load — same answer. The cost is that a server does work on every request, so hosting is more involved than for a static site. Paying for SSR on pages that never change is buying a chef to hand out brochures.

In a modern build this is a per-page decision, not a site-wide one: your homepage and blog can be static (SSG), your product pages server-rendered, and your app's interior screens SPA-style — one codebase, each page served the way it needs. Getting that mix right is much of what you are paying an experienced developer for, and it shows up directly in SEO and perceived speed.