thedaviddias Minimize cumulative layout shift
Layout shifts cause accidental clicks, reading disruption, and user frustration—a good CLS score ensures content stays where users expect it.
Quick Reference
- CLS measures visual stability—target score below 0.1
- Always set width/height on images and embeds
- Reserve space for ads, banners, and dynamic content
- Use transform animations instead of layout-changing properties
Check
Measure CLS using Lighthouse or PageSpeed Insights. Verify score is below 0.1 for good visual stability.
Fix
Reserve space for images/embeds with dimensions, use font-display strategies, and avoid injecting content above existing content.
Explain
Explain how CLS measures visual stability and why unexpected layout shifts frustrate users and cause accidental clicks.
Code Review
Review the routes, assets, and loading behavior that affect Minimize cumulative layout shift. Flag exact files, requests, or rendering steps that add unnecessary network, CPU, or layout cost, and describe the measurement method used to confirm the issue.
For full implementation details, code examples, and framework-specific guidance,
see references/rule.md.
Rule page: https://frontendchecklist.io/en/rules/performance/cumulative-layout-shift