Core Web Vitals: A Practical Checklist for 2026
Stop debating Core Web Vitals and start fixing them. A practical, prioritized checklist.
Core Web Vitals are now a baseline ranking expectation. Three metrics, three target thresholds, dozens of common causes.
LCP under 2.5s
The Largest Contentful Paint is usually the hero image or H1 block. Optimize: preload the hero image, serve modern formats (AVIF/WebP), set explicit width/height, and avoid render-blocking JS above the fold.
INP under 200ms
Replaced FID in March 2024. INP measures responsiveness across the whole page lifecycle, not just first interaction. Break up long JS tasks, defer non-critical scripts, and audit third-party tags ruthlessly.
CLS under 0.1
Reserve space for images, ads and embeds with explicit dimensions or aspect-ratio. Avoid late-injected DOM above existing content. Font swaps are a common silent CLS source — use font-display:optional or preload key fonts.
Tools
Combine PageSpeed Insights (lab + field), Chrome DevTools Performance panel, and the Core Web Vitals Checklist Tool on this site for a complete picture.
Frequently Asked Questions
How much do Core Web Vitals actually move rankings?
Marginally for most queries, dramatically for competitive ones. Treat them as table stakes, not a differentiator.