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Web performance: use profiles to find high-impact issues
Capture Web Vitals and browser traces, with a baseline and measurable verification.
Skills
Confirm the URL, device, network, and available browser/performance tools. Retrieve current web.dev Core Web Vitals and Chrome DevTools/Lighthouse guidance. Capture LCP, INP, CLS, and traces in an authorized scenario; inspect waterfalls, main-thread work, asset size, layout shifts, and compression. Tie each finding to source and measured impact, propose the smallest fix, and retest under the same conditions. Report metrics and caveats; do not rely on a single score or change production config without authorization.
Permissions
Prerequisites
- Diagnose page load, interaction, or visual stability and rank fixes using evidence.
Permissions
- May run browser tests and inspect pages/network; local profiling alone need not alter production.
Limitations
Use an authorized page/environment; report device/network conditions and avoid treating one Lighthouse score as field truth.
Pinned upstream source
- Repository
- cloudflare/skills
- File path
- skills/web-perf/SKILL.md
- Pinned commit
53395984c3ea1925d00fce03b266112302f050e6- Source checked
- 2026-10-14 · Reviewed against the pinned upstream source
Repository metrics
These values describe the upstream repository, not popularity or likes for an individual skill or playbook.
- Stars
- Not collected
- Forks
- Not collected
- Observed at
- Not collected
No metrics snapshot is available yet.
License: Apache-2.0
Compatible tools
Browser performance tooling/MCP · Chrome DevTools · Lighthouse · web.dev guidance
Main topic
Take a coding Agent change from context to verification