What is Server-Side Rendering (SSR) vs Static Site Generation?

Server-side rendering builds each page when a visitor requests it, so the content reflects the database at that moment. Static site generation builds pages ahead of time and serves stored files, which is faster and cheaper but shows whatever was true at the last build. A live stock count needs the first; an About page does not.

Category
Web & Software Engineering
Also called
SSR, SSG, Static site generation, Pre-rendering
Related
Core Web VitalsHeadless CMSWeb HostingContent Management System (CMS)
In our work
Technical consulting

Modern frameworks let both run inside one site, decided page by page, so the choice is not architectural loyalty but a per-page question about how stale the content is allowed to be. A pricing page rebuilt nightly is fine. A booking calendar rebuilt nightly is a support ticket. Between the two sits incremental regeneration, where static pages are rebuilt on a schedule or when the data behind them changes.

What this decides in practice is cost and failure mode. Static pages are files, so they survive traffic spikes and cost almost nothing to serve. Server-rendered pages run code on every request, which means server capacity, caching rules and a slower page when the database is under load. Neither is faster in the abstract, and a badly cached static site can lose to a well-tuned rendered one.

Related terms.

  • Core Web Vitals

    Core Web Vitals are three metrics Google publishes to measure page experience: Largest Contentful Paint (loading, good at 2.5 seconds or under), Interaction to Next Paint (responsiveness, 200 milliseconds or under) and Cumulative Layout Shift (visual stability, 0.1 or under).

    Web & Software Engineering

  • Headless CMS

    A headless CMS stores content without controlling how it is displayed: editors work in an admin interface, and the content is delivered to a website, mobile app or in-store screen through an API.

    Web & Software Engineering

  • Web Hosting

    Web hosting is the paid service that keeps a website’s files on a server connected to the internet so visitors can load them.

    Web & Software Engineering

  • Content Management System (CMS)

    A content management system is software that lets non-technical staff create, edit and publish website content without touching code.

    Web & Software Engineering

Scoping a project?

Reading definitions because you are scoping a project? Skip ahead and just ask.

Tell us what you needBack to the glossary