ReddRadar
Agent skill
web-performance-audit
Web performance audits with Core Web Vitals, bottleneck identification, optimization recommendations. Use for page load times, performance reviews, UX optimization, or encountering LCP, FID, CLS issues, resource blocking, render delays.
Install this agent skill to your Project
npx add-skill https://github.com/secondsky/claude-skills/tree/main/plugins/web-performance-audit/skills/web-performance-audit
SKILL.md
Web Performance Audit
Conduct comprehensive performance audits and implement optimizations.
Core Web Vitals Targets
| Metric | Good | Needs Improvement | Poor |
|---|---|---|---|
| LCP (Largest Contentful Paint) | <2.5s | 2.5-4s | >4s |
| FID (First Input Delay) | <100ms | 100-300ms | >300ms |
| CLS (Cumulative Layout Shift) | <0.1 | 0.1-0.25 | >0.25 |
| INP (Interaction to Next Paint) | <200ms | 200-500ms | >500ms |
Performance Measurement
// Using web-vitals library
import { getCLS, getFID, getLCP, getTTFB } from 'web-vitals';
function sendToAnalytics({ name, value, id }) {
console.log({ name, value, id });
}
getCLS(sendToAnalytics);
getFID(sendToAnalytics);
getLCP(sendToAnalytics);
getTTFB(sendToAnalytics);
Lighthouse Automation
const lighthouse = require('lighthouse');
const chromeLauncher = require('chrome-launcher');
async function runAudit(url) {
const chrome = await chromeLauncher.launch({ chromeFlags: ['--headless'] });
const result = await lighthouse(url, {
port: chrome.port,
onlyCategories: ['performance']
});
await chrome.kill();
return result.lhr;
}
Optimization Strategies
Quick Wins (1-2 days)
- Enable gzip/brotli compression
- Minify CSS/JS
- Defer non-critical scripts
- Optimize images (WebP, lazy loading)
Medium Effort (1-2 weeks)
- Implement code splitting
- Add service worker caching
- Preload critical resources
- Eliminate render-blocking resources
Long-term (1-3 months)
- Architecture improvements
- CDN optimization
- Database query optimization
Performance Budget
{
"timings": [
{ "metric": "first-contentful-paint", "budget": 1500 },
{ "metric": "largest-contentful-paint", "budget": 2500 }
],
"resourceSizes": [
{ "resourceType": "script", "budget": 150 },
{ "resourceType": "image", "budget": 300 }
]
}
Audit Checklist
- Measure baseline Core Web Vitals
- Run Lighthouse audit (mobile & desktop)
- Analyze real user metrics (RUM)
- Identify largest contentful element
- Check for layout shifts
- Review JavaScript bundle size
- Test on slow 3G connection
- Set performance budget
- Configure monitoring alerts
Recommended Agent Skills
Expand your agent's capabilities with these related and highly-rated skills.
secondsky/claude-skills
skill-name
[TODO: Write comprehensive description in third-person. Start with "This skill provides..." or "This skill should be used when..."] [TODO: Add "Use when" scenarios - specific situations where Claude should use this skill] [TODO: Add keywords - technologies, use cases, error messages that should trigger this skill]
secondsky/claude-skills
websocket-implementation
Implements real-time WebSocket communication with connection management, room-based messaging, and horizontal scaling. Use when building chat systems, live notifications, collaborative tools, or real-time dashboards.
secondsky/claude-skills
ai-sdk-ui
secondsky/claude-skills
bun-nextjs
This skill should be used when the user asks about "Next.js with Bun", "Bun and Next", "running Next.js on Bun", "Next.js development with Bun", "create-next-app with Bun", or building Next.js applications using Bun as the runtime.
secondsky/claude-skills
bun-sqlite
Use for bun:sqlite, SQLite operations, prepared statements, transactions, and queries.
secondsky/claude-skills
bun-sveltekit
Use when building or running SvelteKit apps on Bun, including SSR, adapters, and Bun-specific APIs
Didn't find tool you were looking for?