WebPerf: Core Web Vitals

JavaScript snippets for measuring web performance in Chrome DevTools. Execute with mcp__chrome-devtools__evaluate_script, capture output with mcp__chrome-devtools__get_console_message.

Scripts

• scripts/CLS.js — Cumulative Layout Shift (CLS)
• scripts/INP.js — Interaction to Next Paint (INP)
• scripts/LCP-Image-Entropy.js — LCP Image Entropy
• scripts/LCP-Subparts.js — LCP Subparts
• scripts/LCP-Trail.js — LCP Trail
• scripts/LCP-Video-Candidate.js — LCP Video Candidate
• scripts/LCP.js — Largest Contentful Paint (LCP)

Common Workflows

Complete Core Web Vitals Audit