optimizelisted
Install: claude install-skill aiskillstore/marketplace
Identify and fix performance issues to create faster, smoother user experiences.
## Assess Performance Issues
Understand current performance and identify problems:
1. **Measure current state**:
- **Core Web Vitals**: LCP, FID/INP, CLS scores
- **Load time**: Time to interactive, first contentful paint
- **Bundle size**: JavaScript, CSS, image sizes
- **Runtime performance**: Frame rate, memory usage, CPU usage
- **Network**: Request count, payload sizes, waterfall
2. **Identify bottlenecks**:
- What's slow? (Initial load? Interactions? Animations?)
- What's causing it? (Large images? Expensive JavaScript? Layout thrashing?)
- How bad is it? (Perceivable? Annoying? Blocking?)
- Who's affected? (All users? Mobile only? Slow connections?)
**CRITICAL**: Measure before and after. Premature optimization wastes time. Optimize what actually matters.
## Optimization Strategy
Create systematic improvement plan:
### Loading Performance
**Optimize Images**:
- Use modern formats (WebP, AVIF)
- Proper sizing (don't load 3000px image for 300px display)
- Lazy loading for below-fold images
- Responsive images (`srcset`, `picture` element)
- Compress images (80-85% quality is usually imperceptible)
- Use CDN for faster delivery
```html
<img
src="hero.webp"
srcset="hero-400.webp 400w, hero-800.webp 800w, hero-1200.webp 1200w"
sizes="(max-width: 400px) 400px, (max-width: 800px) 800px, 1200px"
loading="lazy"
alt="Hero image"
/>
```
**Reduce JavaSc