SSG definition
Static Site Generation (SSG) is a way of building websites where every page is rendered to plain HTML at build time, before any user visits. The resulting files are served directly from a CDN, so pages load very fast, cost little to host and have a small attack surface, since no server code runs per request.
How does static site generation work?
A static site generator reads content from Markdown files, a headless CMS or a database, combines it with templates or components, and writes one HTML file per page during the build. Assets like CSS, JavaScript and images are optimized at the same time. The output folder is uploaded to a CDN such as Cloudflare, Netlify, Vercel or Amazon CloudFront, which serves the files from locations close to each visitor without contacting an application server.
Worked example: a software company keeps 2,000 documentation pages in Markdown in the same Git repository as its code. Each merged pull request triggers a build in CI, the generator renders every page, and the CDN switches to the new version atomically. If a broken page slips through, rolling back simply means redeploying the previous build.
Popular static site generators
Generators range from pure static tools to full frameworks that support static output alongside server rendering. The right choice depends on how much interactivity the site needs, which languages the team knows and how many pages must be built on each deploy.
- Astro: content-focused, ships little JavaScript by default
- Next.js: static generation per route plus incremental regeneration
- Hugo: written in Go and known for very fast builds of large sites
- Eleventy: simple, flexible and template-language agnostic
- Docusaurus, VitePress and Jekyll for blogs and documentation
SSG vs SSR
Static generation does the rendering work once per deploy, while server-side rendering does it on every request. SSG is faster and cheaper but content is only as fresh as the last build. SSR always shows current data but needs servers and careful caching. The classic weakness of SSG, long builds for sites with thousands of pages, is addressed by incremental static regeneration, which rebuilds individual pages on demand or when a CMS webhook fires.
Benefits and limitations of SSG
The benefits follow from doing work ahead of time. Pages load fast because there is nothing to compute per request, hosting is cheap because a CDN serves files, and the attack surface is small because no application server or database sits behind page views. Static sites also stay online during traffic spikes that would overwhelm a single server.
The limits are freshness and build time. Content changes only appear after a rebuild or regeneration, very large sites can take a long time to build, and editors need a preview environment to see drafts. Anything personal to the visitor, such as a cart or account details, has to load separately in the browser.
When to use static site generation
SSG is ideal for marketing sites, blogs, documentation, landing pages, glossaries and product catalogs that change a few times a day at most. It is a poor fit for pages that depend on the logged-in user or real-time data, though those parts can be loaded client-side on top of a static shell. Nexzem uses static generation for content-heavy corporate sites so they score well on Core Web Vitals and survive traffic spikes without scaling servers.