mxa-audit-performance
Assesses a site's Core Web Vitals on a sample of its pages, measured by Lighthouse, and names the causes rather than only the timings. Lab and field numbers are never confused.
- Measures loading, layout shift and blocking time with Lighthouse on every sampled page, and reports the slowest.
- Takes the causes behind each number, such as an unsized image or a blocking script, from Lighthouse's own diagnostics, with the timing beside each.
- Keeps lab and field apart, reads the field numbers from the Chrome UX Report where a key is present, and explains why the two disagree when they do.
- Reports a metric it could not measure as unmeasured, never as an estimate.
- Writes a summary for the client and a fix list, then confirms each fix landed.
What is inside
The checks module maps Lighthouse's timings and diagnostics, and the Chrome UX Report's field numbers, onto the three Core Web Vitals; it reads no markup itself.
- Uses
- LighthouseChrome UX Report
- Reference
- references/cwv.mdreferences/react-next.md
- Evals
- 3
Works with
The outside tools and connectors this skill drives.
- Lighthouse and the Chrome UX Report· our default
- WebPageTest
- Vercel Speed Insights
The first is what we reach for on our own projects. A project that already uses one of the others keeps it, and the skill works with that instead.