Performance Audit Skill
Analyze web page performance using Web Vitals and network timing metrics.
When to Use
This skill activates when:
- •User asks about page performance or speed
- •User wants to optimize load times
- •User mentions slow page or poor user experience
- •User needs Core Web Vitals metrics
- •User asks about SEO performance factors
Capabilities
Web Vitals Analysis
- •Get Core Web Vitals (
o11y_get-web-vitals)- •LCP (Largest Contentful Paint)
- •INP (Interaction to Next Paint)
- •CLS (Cumulative Layout Shift)
- •TTFB (Time to First Byte)
- •FCP (First Contentful Paint)
Network Performance
- •Analyze request timing (
o11y_get-http-requests) - •Identify slow API calls
- •Check resource sizes
- •Find blocking resources
Visual Analysis
- •Capture page at different load stages
- •Identify layout shifts visually
- •Check above-the-fold content
JavaScript Analysis
- •Profile JavaScript execution
- •Check for long tasks
- •Identify render-blocking scripts
Performance Thresholds
| Metric | Good | Needs Work | Poor |
|---|---|---|---|
| LCP | ≤2.5s | 2.5-4s | >4s |
| INP | ≤200ms | 200-500ms | >500ms |
| CLS | ≤0.1 | 0.1-0.25 | >0.25 |
| TTFB | ≤800ms | 800-1800ms | >1800ms |
Audit Workflow
- •Baseline: Get initial Web Vitals metrics
- •Network: Analyze slow/large requests
- •Resources: Check for render-blocking resources
- •JavaScript: Look for long tasks
- •Images: Check for unoptimized images
- •Report: Summarize with recommendations
Common Issues
- •Large unoptimized images
- •Render-blocking CSS/JS
- •Too many HTTP requests
- •Slow server response (TTFB)
- •Layout shifts from dynamic content
- •Uncompressed resources