<objective> Checks image SEO fundamentals: descriptive `alt` text (empty only for decorative images), kebab-case descriptive filenames, modern formats (WebP/AVIF with JPG/PNG fallback), `loading="lazy"` on below-fold images, responsive `srcset`/`sizes`, explicit `width`/`height` to prevent CLS, ImageObject schema, and file-size/quality targets per image role (hero/content/thumbnail). </objective>

Image SEO

Checks

• All <img> have descriptive alt (empty alt="" only for decorative)
• Filenames: kebab-case, descriptive (red-running-shoes.webp not IMG_1234.jpg)
• Formats: WebP/AVIF with JPG/PNG fallback
• Lazy loading: loading="lazy" on below-fold images
• Responsive: srcset + sizes for different viewports
• Dimensions: width + height set to prevent CLS

File Optimization Targets

Type	Format	Max size	Quality
Hero	AVIF/WebP	200 KB	75-80
Content	WebP	100 KB	75
Thumbnail	WebP	30 KB	70

References

• skills/seo/02-onpage-seo/alt-text-images.md