Static Site Generation pre-renders all pages at build time, producing plain HTML files that can be served directly from a CDN without any server-side processing. Every visitor receives the same pre-built file, making SSG the fastest and most cost-effective way to deliver web content.
How It Works
During the build process, the framework runs your page components, fetches data from APIs, databases, or files, and generates HTML for every possible route. These files are deployed to a CDN edge network. When a user visits a page, the nearest CDN node returns the cached HTML instantly with no database queries, no server rendering, and no delay.
In Next.js, pages using getStaticProps are statically generated. For dynamic routes (like blog posts), getStaticPaths tells the build which pages to generate. Incremental Static Regeneration (ISR) lets you update individual pages after deployment without rebuilding the entire site.
Why It Matters
SSG delivers unmatched performance. Pre-rendered HTML served from a CDN achieves sub-100ms load times globally. There is no server to scale, no database to crash under traffic spikes, and hosting costs are near zero. A statically generated site can handle millions of visitors on a $20/month hosting plan.
Security improves too. With no server processing requests, the attack surface shrinks dramatically. There is no SQL injection vector, no server-side vulnerabilities, and no dynamic content to exploit.
In Practice
Documentation sites like React's official docs use SSG because content changes only when developers publish updates. The build compiles hundreds of markdown files into optimized HTML pages with full-text search indexes generated at build time. Deploys take minutes and the result serves globally at edge speed.
Common Mistakes
SSG struggles with highly dynamic content. If your page shows real-time data, user-specific information, or content that updates every few seconds, pure SSG is not the right fit. Build times also grow linearly with page count; a site with 100,000 product pages might take an hour to build. ISR or on-demand revalidation solves this by regenerating only changed pages.