Image SEO: Optimization for Google, Accessibility and Speed

Choose images that add information

Use original diagrams, product views, process visuals and evidence where they improve understanding. Decorative images rarely deserve keyword-focused alt text or prominent loading priority.

Place relevant images near the text that explains them and use descriptive surrounding headings and captions where useful.

Write alt text for its actual purpose

Describe the information or function a user would miss if the image were unavailable. Keep decorative images empty and avoid repeating nearby text or stuffing keywords.

For linked images, describe the destination or action when that is more useful than the visual appearance.

Deliver the smallest suitable resource

Select modern formats based on content, provide responsive candidates and avoid serving desktop dimensions to small screens. Compress to the point where quality remains appropriate for the use case.

• Set intrinsic width and height to prevent layout shift
• Use srcset and sizes for responsive rendering
• Prefer SVG for suitable vector graphics
• Use WebP or AVIF where the delivery stack supports them
• Cache immutable image assets effectively

Protect the largest contentful image

Do not lazy-load the likely LCP image. Make it discoverable in the initial HTML, prioritize it carefully and avoid loading competing oversized assets above the fold.

Lazy-load off-screen images and use asynchronous decoding where appropriate.

Support discovery and measurement

Use crawlable image URLs, accurate structured data and image sitemap extensions for important editorial or product images. Keep image URLs stable where possible.

Monitor Core Web Vitals, transfer size, rendering dimensions, broken assets and image-search performance in Search Console.