Core Web Vitals in 2026: A Practical Checklist
A no-nonsense checklist for passing Core Web Vitals - LCP, INP and CLS - with the fixes that actually move the needle on real websites.
Core Web Vitals are a real ranking signal and, more importantly, a real user experience signal. Fast, stable pages convert better and rank better. Here's the practical checklist we run on every site.
The three metrics
- LCP (Largest Contentful Paint) - how fast the main content loads. Target: under 2.5s.
- INP (Interaction to Next Paint) - how responsive the page feels to input. Target: under 200ms.
- CLS (Cumulative Layout Shift) - how much the layout jumps around. Target: under 0.1.
LCP checklist
- Serve modern image formats (WebP/AVIF) and correctly sized responsive images.
- Preload the hero image and critical fonts; use
font-display: swap. - Inline critical CSS and defer the rest.
- Put your site on a CDN and cache aggressively.
- Avoid render-blocking third-party scripts above the fold.
INP checklist
- Ship less JavaScript. Every kilobyte you don't send is a kilobyte the main thread doesn't parse.
- Break up long tasks; defer non-critical work.
- Prefer CSS for animations and interactions where possible.
- Audit third-party tags - analytics and chat widgets are common culprits.
CLS checklist
- Always set explicit
width/height(oraspect-ratio) on images and embeds. - Reserve space for ads, banners and dynamically injected content.
- Avoid inserting content above existing content after load.
- Use
font-display: swapwith a well-matched fallback to reduce text shift.
How to measure
Use PageSpeed Insights and Search Console's Core Web Vitals report for field data (real users), and Lighthouse for lab testing while you work. Field data is what Google actually uses - so a perfect Lighthouse score with poor field data still needs work.
The shortcut
Honestly? The biggest wins usually come from shipping less JavaScript and optimizing images. Nail those two and most sites pass. Want us to check yours? Start with a free audit.