Definition
Pre-rendering is a technique that generates the complete HTML of each page in advance (at build time or at regular intervals), rather than on-the-fly with each request. Several approaches exist: Static Site Generation (SSG) which generates all pages at build (Gatsby, Next.js export), Incremental Static Regeneration (ISR) which regenerates stale pages in the background, and on-demand pre-rendering which generates HTML on first access and then caches it. For SEO, pre-rendering guarantees that search engines receive complete HTML immediately, without waiting for JavaScript rendering. It is the best-performing solution in terms of TTFB and Core Web Vitals.
Key Points
- Generates static HTML in advance for optimal TTFB
- SSG for stable content, ISR for regularly changing content
- Guarantees immediate and complete indexation by search engines
Practical Examples
SSG with Next.js
A blog with 500 articles uses Next.js in SSG mode: all pages are generated as HTML at build time. TTFB is under 50ms and all pages are indexed within 48 hours.
ISR for a product catalog
An e-commerce site uses Next.js ISR with a 60-second revalidate for its product pages: static HTML is served instantly and regenerated in the background when stale.
Frequently Asked Questions
SSR generates HTML on each request (on-the-fly), while pre-rendering generates HTML in advance (at build). Pre-rendering offers better TTFB because it serves static files, but it is less suited for content that changes very frequently.
Yes, with solutions like Next.js ISR (Incremental Static Regeneration). Instead of pre-rendering all pages at build, only the most popular pages are generated initially, while others are rendered and cached on first visit.
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Last updated: 2026-02-07