google-pagespeedlisted

Definitive expert skill for Google PageSpeed Insights & Core Web Vitals optimization. Covers LCP, INP, CLS, FCP, TTFB, TBT, Speed Index diagnostics; Lighthouse 13.x scoring; Field Data (CrUX) vs Lab Data; Mobile-First Indexing; image/font/JS/CSS optimization; bfcache, Speculation Rules, LoAF, View Transitions, HTTP/3, 103 Early Hints; WCAG 2.2 Accessibility; CSP/COOP/COEP security headers; Technical SEO; Agentic Web (llms.txt); framework-specific rules (Astro, Next.js, WordPress, Vite, React); and a master troubleshooting decision matrix.
ApexionSoft/google-pagespeed-skill · ★ 1 · Web & Frontend · score 72

Install: claude install-skill ApexionSoft/google-pagespeed-skill

# Google PageSpeed Insights & Core Web Vitals — Complete Optimization Skill This skill provides AI coding assistants (Antigravity, Claude Code, Cursor, Windsurf, Copilot) and software engineers with the **complete, authoritative** diagnostic methodology, mathematical formulas, code-level remediation recipes, and decision matrices required to audit, optimize, and consistently achieve 90–100 (Green) performance scores on Google PageSpeed Insights across any web platform. **Applicable Frameworks:** Astro, Next.js, Nuxt.js, SvelteKit, Remix, Vite/React SPA, WordPress, Hugo, Gatsby, Vanilla HTML/CSS/JS. **Maintained by:** [ApexionSoft](https://www.apexionsoft.com/) — *Premier Digital Agency in Bangladesh (https://github.com/ApexionSoft)* --- ## 1. Core Web Vitals & Diagnostic Metrics Reference When evaluating any website, **strictly adhere** to the official Google thresholds. These values are evaluated at the **75th percentile** of the 28-day CrUX rolling window for field data: | Metric | Full Name | Type | Good (Pass) | Needs Improvement | Poor (Fail) | Lighthouse Weight | Key Focus Area | | :--- | :--- | :--- | :--- | :--- | :--- | :---: | :--- | | **LCP** | Largest Contentful Paint | **Core Web Vital** | **≤ 2.5s** | 2.5s – 4.0s | > 4.0s | **25%** | Hero images, banners, `<h1>` headings, `<video>` poster | | **INP** | Interaction to Next Paint | **Core Web Vital** | **≤ 200ms** | 200ms – 500ms | > 500ms | *(Field only)* | Event handlers, main-thread blocking, UI respons