Performance Audit Websites

Use this skill to keep premium sites fast enough that visual ambition does not punish users. Measure first and optimize the dominant constraint; do not apply framework folklore as proof.

Own measured diagnosis and implementation. Route pre-build numeric budgets, acceptance thresholds, and visual-richness policy to $performance-budget-lab.

Workflow

1. Inspect the affected surface, relevant project scripts, target URL and available inspection tooling; reuse existing context.
2. Read Performance Audit Websites Guide before claiming the site is ready. For React or Next.js implementation work, also read React and Next.js performance.
3. Record a reproducible baseline and identify the dominant request, rendering, interaction or layout-shift cost. When optimization is authorized, change the measured bottleneck and compare under matched build/device/cache conditions.
4. Fix issues when they are in scope; otherwise record exact evidence and remaining risk.
5. Summarize commands, URLs, screenshots/checks, changed files, and what was not tested.

Separate field data, controlled lab data, source inspection, and inference. A Lighthouse score from one machine is not a field-performance guarantee; an optimized source pattern is not a measured user improvement.

Scoped execution

Apply the shared web contract once when execution crosses phases; reuse it if already read. Load only the specialist guidance relevant to the requested surface and deliverable.