Static Site Generation (SSG)
Short definition
Static site generation means a page's HTML is built once before publishing and then served as a ready file, without rebuilding it per visit.
When content changes, a developer or content management system triggers a build, during which the full HTML for every page is generated in advance. When a visitor arrives, the server simply sends that ready file, with no calculation done at that moment.
You meet it on content that does not change often, such as blog posts, service pages and corporate pages; these can be served very fast from a CDN.
It is often confused with server-side rendering (SSR). SSR rebuilds the page on every request, while SSG builds once and serves the same file repeatedly, making SSG faster but less suited to content that must update instantly.
The most common mistake is not noticing that an update to the content did not trigger a new build, so the server and CDN keep serving the old file and visitors never see the change. The correct approach is to make sure every content change automatically triggers a build as part of publishing, and to purge the CDN cache when needed.
Why it matters
Pre-built pages place almost no load on the server and load fast worldwide from a CDN. For content that rarely changes, this is the most efficient route for both speed and hosting cost.
Illustrative example
A workwear manufacturer's category pages update only a few times a month, so they are statically generated and load instantly from a CDN with no server load per visit.
