Server-Side Rendering (SSR)

Generating full HTML on the server for each request so search engines receive complete content immediately.

SSR produces complete HTML pages on the server before sending them to the browser, meaning Googlebot receives fully-rendered content in the initial HTTP response without needing to execute JavaScript. This eliminates the two-wave indexing delay that client-side rendered (CSR) JavaScript applications face.

For SEO, SSR ensures: all page content is indexable immediately, metadata (title, description, OG tags) is always present in the HTML head, links are discoverable in the first crawl, and structured data is visible without JS execution. Next.js, Nuxt.js, SvelteKit, and Remix all support SSR.

StaticGeneration (SSG/pre-rendering) is an alternative approach that generates HTML at build time rather than per-request. SSG is even better for SEO (fastest TTFB, CDN-cacheable) but requires a build step when content changes. Incremental Static Regeneration (ISR) in Next.js combines the SEO benefits of SSG with the freshness of SSR.