image-optimization
Installation
SKILL.md
Image Optimization — SEO & Core Web Vitals
Images are 50-70% of page weight on most sites. They are also the most common LCP element. Wrong format, wrong loading strategy, or missing dimensions are among the top 5 CWV failure causes.
Format selection
| Format | Best for | Browser support | Typical savings vs JPEG |
|---|---|---|---|
| JPEG | Photos, complex images | Universal | baseline |
| PNG | Graphics with transparency | Universal | baseline |
| WebP | Photos + graphics | 95%+ (2024) | 25-35% smaller |
| AVIF | Photos + graphics | 80%+ (2024) | 40-50% smaller |
| SVG | Icons, logos, illustrations | Universal | N/A (vector) |