CSR

SSR

SSG

ISR

Feature / Aspect CSR (Client-Side Rendering) SSR (Server-Side Rendering) SSG (Static Site Generation) ISR (Incremental Static Regeneration)
Rendering Location Browser Server per request Build time Build + runtime
HTML Delivery Minimal HTML, JS bundle Fully rendered HTML Fully rendered static HTML Fully rendered static HTML, revalidated periodically
Data Fetching Browser fetches API after page load Server fetches API per request During build only During build + background regeneration
Initial Load Speed Slow first paint Fast first paint (depends on server) Very fast (CDN served) Very fast (CDN served)
Subsequent Navigation Fast (SPA behavior) Fast (with caching) Fast (static pages) Fast (static pages)
SEO Poor (bots see empty HTML unless hydrated) Excellent Excellent Excellent
Server Load Low High (each request rendered) Low Medium (regeneration triggered by request)
Hydration Needed Yes Yes Optional Optional
Content Freshness Real-time Real-time Static, updates require rebuild Near real-time (depends on revalidate interval)
Rebuild Requirement None None Full rebuild for content change Only updated pages regenerated automatically
Cost Low (CDN + simple server) Higher (server per request) Very low (CDN hosting) Medium (CDN + background regeneration)
Security JS-heavy, exposes API endpoints Server-controlled Static, highly secure Static + server regeneration
Scalability High (mostly CDN & client load) Moderate (server can bottleneck) Very high (CDN only) High (depends on regeneration frequency)
Caching Browser cache only Possible server & CDN caching CDN cache CDN cache + regeneration
Best Use Cases Dashboards, Admin panels, Internal tools, Auth apps Dynamic pages, Personalized content, SEO-critical pages Blogs, Docs, Marketing landing pages News sites, Product catalogs, Content with periodic updates