perf-astro
Astro-specific performance optimizations for 95+ Lighthouse scores. Covers critical CSS inlining, compression, font loading, and LCP optimization. Use when optimizing Astro site performance, improving Astro Lighthouse scores, or configuring astro-critters. Do NOT use for non-Astro sites (use perf-web-optimization or core-web-vitals) or running Lighthouse audits (use perf-lighthouse).
Best use case
perf-astro is best used when you need a repeatable AI agent workflow instead of a one-off prompt.
Astro-specific performance optimizations for 95+ Lighthouse scores. Covers critical CSS inlining, compression, font loading, and LCP optimization. Use when optimizing Astro site performance, improving Astro Lighthouse scores, or configuring astro-critters. Do NOT use for non-Astro sites (use perf-web-optimization or core-web-vitals) or running Lighthouse audits (use perf-lighthouse).
Teams using perf-astro should expect a more consistent output, faster repeated execution, less prompt rewriting.
When to use this skill
- You want a reusable workflow that can be run more than once with consistent structure.
When not to use this skill
- You only need a quick one-off answer and do not need a reusable workflow.
- You cannot install or maintain the underlying files, dependencies, or repository context.
Installation
Claude Code / Cursor / Codex
Manual Installation
- Download SKILL.md from GitHub
- Place it in
.claude/skills/perf-astro/SKILL.mdinside your project - Restart your AI agent — it will auto-discover the skill
How perf-astro Compares
| Feature / Agent | perf-astro | Standard Approach |
|---|---|---|
| Platform Support | Not specified | Limited / Varies |
| Context Awareness | High | Baseline |
| Installation Complexity | Unknown | N/A |
Frequently Asked Questions
What does this skill do?
Astro-specific performance optimizations for 95+ Lighthouse scores. Covers critical CSS inlining, compression, font loading, and LCP optimization. Use when optimizing Astro site performance, improving Astro Lighthouse scores, or configuring astro-critters. Do NOT use for non-Astro sites (use perf-web-optimization or core-web-vitals) or running Lighthouse audits (use perf-lighthouse).
Where can I find the source code?
You can find the source code on GitHub using the link provided at the top of the page.
SKILL.md Source
# Astro Performance Playbook
Astro-specific optimizations for 95+ Lighthouse scores.
## Quick Setup
```bash
npm install astro-critters @playform/compress
```
```js
// 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=mobile
```
See also:
- **perf-lighthouse** - Running audits, reading reports, setting budgets
- **perf-web-optimization** - Core Web Vitals, bundle size, caching strategies
## Checklist
- [ ] `astro-critters` installed and configured
- [ ] `@playform/compress` installed and configured
- [ ] Google Fonts use `media="print" onload` pattern
- [ ] Third-party scripts deferred to user interaction
- [ ] LCP images preloaded in `<head>`Related Skills
perf-lighthouse
Run Lighthouse audits locally via CLI or Node API, parse and interpret reports, and set performance budgets. Use when measuring site performance, understanding Lighthouse scores, setting up budgets, or integrating audits into CI. Triggers on: lighthouse, run lighthouse, lighthouse score, performance audit, performance budget. Do NOT use for fixing specific performance issues (use perf-web-optimization or core-web-vitals) or Astro-specific optimization (use perf-astro).
perf-web-optimization
Optimize web performance: bundle size, images, caching, lazy loading, and overall page speed. Use when site is slow, reducing bundle size, fixing layout shifts, improving Time to Interactive, or optimizing for Lighthouse scores. Triggers on: web performance, bundle size, page speed, slow site, lazy loading. Do NOT use for Core Web Vitals-specific fixes (use core-web-vitals), running Lighthouse audits (use perf-lighthouse), or Astro-specific optimization (use perf-astro).
technical-design-doc-creator
Creates comprehensive Technical Design Documents (TDD) with mandatory and optional sections through interactive discovery. Use when user asks to "write a design doc", "create a TDD", "technical spec", "architecture document", "RFC", "design proposal", or needs to document a technical decision before implementation. Do NOT use for README files, API docs, or general documentation (use docs-writer instead).
cloudflare-deploy
Deploy applications and infrastructure to Cloudflare using Workers, Pages, and related platform services. Use when the user asks to deploy, host, publish, or set up a project on Cloudflare. Do NOT use for deploying to Vercel, Netlify, or Render (use their respective skills).
figma
Use the Figma MCP server to fetch design context, screenshots, variables, and assets from Figma, and to translate Figma nodes into production code. Use when a task involves Figma URLs, node IDs, design-to-code implementation, or Figma MCP setup and troubleshooting. Covers general Figma data fetching and exploration. Do NOT use when the goal is specifically pixel-perfect code implementation from a Figma design (use figma-implement-design instead).
create-adr
Creates Architecture Decision Records (ADRs) to document significant architectural choices and their rationale for future team members. Use when the user says "write an ADR", "document this decision", "record why we chose X", "add an architecture decision record", "create an ADR for", or wants to capture the reasoning behind a technical choice so the team understands it later. Do NOT use when the decision hasn't been made yet (use create-rfc instead), for implementation planning (use technical-design-doc-creator), or for general documentation.
frontend-blueprint
AI frontend specialist and design consultant that guides users through a structured discovery process before generating any code. Collects visual references, design tokens, typography, icons, layout preferences, and brand guidelines to ensure the final output matches the user's vision with high fidelity. Use when the user asks to build, design, create, or improve any frontend interface — websites, landing pages, dashboards, components, apps, emails, forms, modals, or any UI element. Also triggers on "build me a UI", "design a page", "create a component", "improve this layout", "make this look better", "frontend", "interface", "redesign", or when the user provides mockups, screenshots, or design references. Do NOT use for backend logic, API design, database schemas, or non-visual code tasks.
component-identification-sizing
Maps architectural components in a codebase and measures their size to identify what should be extracted first. Use when asking "how big is each module?", "what components do I have?", "which service is too large?", "analyze codebase structure", "size my monolith", or planning where to start decomposing. Do NOT use for runtime performance sizing or infrastructure capacity planning.
coupling-analysis
Analyzes coupling between modules using the three-dimensional model (strength, distance, volatility) from "Balancing Coupling in Software Design". Use when asking "are these modules too coupled?", "show me dependencies", "analyze integration quality", "which modules should I decouple?", "coupling report", or evaluating architectural health. Do NOT use for domain boundary analysis (use domain-analysis) or component sizing (use component-identification-sizing).
domain-analysis
Maps business domains and suggests service boundaries in any codebase using DDD Strategic Design. Use when asking "what are the domains in this codebase?", "where should I draw service boundaries?", "identify bounded contexts", "classify subdomains", "DDD analysis", or analyzing domain cohesion. Do NOT use for grouping existing components into domains (use domain-identification-grouping) or dependency analysis (use coupling-analysis).
domain-identification-grouping
Groups existing components into logical business domains to plan service-based architecture. Use when asking "which components belong together?", "group these into services", "organize by domain", "component-to-domain mapping", or planning service extraction from an existing codebase. Do NOT use for identifying new domains from scratch (use domain-analysis) or analyzing coupling (use coupling-analysis).
aws-advisor
Expert AWS Cloud Advisor for architecture design, security review, and implementation guidance. Leverages AWS MCP tools for accurate, documentation-backed answers. Use when user asks about AWS architecture, security, service selection, migrations, troubleshooting, or learning AWS. Triggers on AWS, Lambda, S3, EC2, ECS, EKS, DynamoDB, RDS, CloudFormation, CDK, Terraform, Serverless, SAM, IAM, VPC, API Gateway, or any AWS service. Do NOT use for non-AWS cloud providers or general infrastructure without AWS context.