Image SEO basics
In one line
Image SEO means optimising images so they load fast, are accessible, and can rank, through compression, descriptive filenames and alt text, and the right formats.
How to do it
- Compress images and use modern formats (WebP/AVIF)
- Descriptive filenames (blue-running-shoes.jpg, not IMG_123.jpg)
- Specific alt text describing the image (helps accessibility + search)
- Correct dimensions and lazy-loading below the fold
- Add image structured data where relevant
Why it matters
Images affect page speed (a ranking factor) and can rank in image search, driving extra traffic. Alt text also helps screen readers and gives AI engines context to understand and describe your visuals.
Frequently asked
What image format is best for SEO?
Modern formats like WebP or AVIF, they're much smaller than JPEG/PNG at similar quality, improving load speed.
Does alt text help ranking?
It helps images rank in image search and improves accessibility; it also gives search and AI context about the image.
Put this into practice
Grade your site against our 250-point AEO/GEO checklist and see exactly what to fix, free, no signup.