How to use
- Copy the installation command and review the source package before installing it in your own agent environment.
- Check the source document for required tools, credentials and supported hosts.
- Describe your input and desired deliverable; review the output against the source material.
npx skills add https://github.com/tech-leads-club/agent-skills --skill perf-astroBefore you start
- Installation does not include a model subscription, API allowance or permission to access your files.
- Repository stars and installation counts describe activity, not an independent quality or security test.
Original skill document
Rendered from the source repository. Headings, examples, code, tables, links, and referenced images are preserved.
Astro Performance Playbook
Astro-specific optimizations for 95+ Lighthouse scores.
Quick Setup
bash
npm install astro-critters @playform/compressjs
// astro.config.mjs
import { defineConfig } from 'astro/config'
import critters from 'astro-critters'
import compress from '@playform/compress'
export default defineConfig({
integrations: [
critters(),
compress({
CSS: true,
HTML: true,
JavaScript: true,
Image: false,
SVG: false,
}),
],
})Integrations
astro-critters
Automatically extracts and inlines critical CSS. No configuration needed.
What it does:
- Scans rendered HTML for above-the-fold elements
- Inlines only the CSS those elements need
- Lazy-loads the rest
Build output shows what it inlined:
Inlined 40.70 kB (80% of original 50.50 kB) of _astro/index.xxx.css.@playform/compress
Minifies HTML, CSS, and JavaScript in the final build.
Options:
js
compress({
CSS: true, // Minify CSS
HTML: true, // Minify HTML
JavaScript: true, // Minify JS
Image: false, // Skip if using external image optimization
SVG: false, // Skip if SVGs are already optimized
})Layout Pattern
Structure your Layout.astro for performance:
astro
---
import '../styles/global.css'
---
<!doctype html>
<html lang="pt-BR">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<!-- Font fallback (prevents FOIT) -->
<style>
@font-face {
font-family: 'Inter';
font-display: swap;
src: local('Inter');
}
</style>
<!-- Non-blocking Google Fonts -->
<link rel="preconnect" href="https://fonts.googleapis.com">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link
rel="stylesheet"
href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700&display=swap"
media="print"
onload="this.media='all'"
/>
<noscript>
<link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700&display=swap">
</noscript>
<!-- Preload LCP images -->
<link rel="preload" as="image" href="/hero.png" fetchpriority="high">
<title>{title}</title>
<!-- Defer third-party scripts -->
<script>
let loaded = false;
function loadAnalytics() {
if (loaded) return;
loaded = true;
// Load GTM, analytics, etc.
}
['scroll', 'click', 'touchstart'].forEach(e => {
document.addEventListener(e, loadAnalytics, { once: true, passive: true });
});
setTimeout(loadAnalytics, 5000);
</script>
</head>
<body>
<slot />
</body>
</html>Measuring
bash
npx lighthouse https://your-site.com --preset=perf --form-factor=mobileSee also:
- perf-lighthouse - Running audits, reading reports, setting budgets
- perf-web-optimization - Core Web Vitals, bundle size, caching strategies
Checklist
- [ ]
astro-crittersinstalled and configured - [ ]
@playform/compressinstalled and configured - [ ] Google Fonts use
media="print" onloadpattern - [ ] Third-party scripts deferred to user interaction
- [ ] LCP images preloaded in
<head>
