PageSpeed Performance Audit

Audit URL: $ARGUMENTS

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Step 1 — Pre-flight (pagespeed-perf skill)

Invoke pagespeed-perf skill.

Read PAGESPEED_API_KEY from the environment. Compute the output filename: {YYYY-MM-DD}_pagespeed-{hostname}-claude.md.

Log whether the API key was found. Proceed regardless — lab data is available without a key, but CrUX field data requires it.

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Step 2 — Collect

Call the PageSpeed Insights API for the URL provided above.

• Strategy: both (mobile + desktop) unless the user specified otherwise.
• Call PSI directly via WebFetch and fetch the HTML source for manual resource-hint analysis.

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Step 3 — Analyze

Extract from the PSI response:

• Core Web Vitals: LCP, INP, CLS, FCP, TBT, TTFB
• LCP element (type, selector, HTML snippet)
• Third-party scripts ordered by blocking time
• Render-blocking resources
• Unused JavaScript and CSS (savings in bytes and ms)

From the HTML source:

• Resource hints (<link rel="preload|preconnect|prefetch">)
• Images: lazy loading, fetchpriority, format, dimensions
• Fonts: font-display, preloaded subsets
• Blocking scripts in <head> (no async/defer)

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Step 4 — Prioritize

Score each identified optimization using the 80/20 matrix: Score = Impact × Ease (each 1–5, max 25).

Order findings by descending score. Mark optimizations with Score ≥ 20 as Critical 20%.

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Step 5 — Report

Write the full performance report to {YYYY-MM-DD}_pagespeed-{hostname}-claude.md in the current directory.

Required sections:

1. Resumen Ejecutivo (2–3 paragraphs)
2. Métricas Actuales (lab vs field table)
3. Recursos con Mayor Impacto
4. Plan de Acción Priorizado (80/20 table)
5. Solución Técnica Detallada (per finding: problem, evidence, code, expected gain)
6. Quick Wins / High Impact Changes / Roadmap

End every report with:

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*Informe generado el {YYYY-MM-DD} · Herramienta: Claude Code + pagespeed-perf skill*
*API Key usada: {Sí / No} · Datos CrUX: {Disponibles / No disponibles}*

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Requirements

PAGESPEED_API_KEY — Optional but strongly recommended.

• With key: real CrUX field data + 25,000 requests/day quota.
• Without key: lab data only (Lighthouse); shared rate limit applies.

Set in your shell:

$env:PAGESPEED_API_KEY = "your-api-key"   # Windows PowerShell
export PAGESPEED_API_KEY="your-api-key"    # macOS / Linux

Get a free key: https://developers.google.com/speed/docs/insights/v5/get-started