Static sites often start fast, then gradually slow down as teams add analytics, embeds, heavier fonts, and large images. Core Web Vitals give you a practical way to measure speed and stability from real users and focus on fixes that matter.
Know what you are optimising
Core Web Vitals focus on user experience:
- LCP (Largest Contentful Paint). How quickly the main content appears.
- INP (Interaction to Next Paint). How responsive the page is to input.
- CLS (Cumulative Layout Shift). How stable the layout is as content loads.
Simple LCP improvements
LCP is usually dominated by images, fonts, and blocking scripts. Common fixes:
- Optimise hero images. Serve appropriately sized images and avoid huge originals.
- Prefer modern formats. Use WebP/AVIF where possible.
- Reduce render-blocking JS. Defer non-essential scripts.
- Use caching properly. Static assets should be long-lived and content-addressed.
Keep INP low by reducing work on the main thread
INP often degrades when sites load too much JavaScript. For static sites:
- Remove unused libraries and widgets.
- Load scripts only on pages that need them.
- Prefer simple HTML and CSS interactions over JS where possible.
Prevent CLS with layout discipline
CLS is often self-inflicted. Improve it by:
- Setting image dimensions. Always specify width/height or use CSS aspect-ratio boxes.
- Reserving space for dynamic content. Avoid injecting banners that push content down.
- Being careful with fonts. Use font-display settings that avoid big layout shifts.
Measure the right way
Lab tools are helpful, but real users are the truth. Combine:
- Search Console Core Web Vitals reports for field data.
- Lighthouse for repeatable lab checks.
- RUM (real user monitoring) if you operate a large site.
Make performance part of your technical SEO audits
Performance is not separate from SEO; it is part of page quality. Add vitals checks to your audit process (see technical SEO audits).
Static sites win when they stay simple. A small set of performance rules applied consistently is usually enough to keep Core Web Vitals healthy.