What Is Server-Side Rendering (SSR) vs Client-Side Rendering (CSR)

Short answer

Server-Side Rendering generates HTML on the server for each request. Client-Side Rendering builds the page in the browser using JavaScript. Each approach has distinct trade-offs.

Key differences

• Initial load: SSR sends ready HTML; CSR requires JS download and execution first.
• Interactivity: CSR offers app-like transitions after the initial load.
• SEO: SSR provides immediately crawlable content; CSR needs prerendering or hydration.
• Server load: SSR uses more server CPU per request; CSR offloads work to the client.

When to use each

• Use SSR for content-heavy sites, blogs, and e-commerce where SEO and fast FCP matter.
• Use CSR for dashboards, internal tools, and highly interactive applications where user state is complex.