Image SEO
Definition
Optimising images to rank in image search and improve page SEO. Includes file names, alt text, compression, and proper formatting.
What is Image SEO?
Image SEO is the practice of optimising images so they rank in Google Images and contribute positively to your page's overall SEO. Properly optimised images can drive significant traffic while poorly optimised ones slow your site and waste ranking opportunities.
Google Images accounts for over 20% of all Google searches, making image SEO a genuine traffic opportunity.
Key Image SEO Elements
File Names
Use descriptive, keyword-relevant file names before uploading.
| Bad | Good |
|---|---|
| IMG_3847.jpg | exeter-web-design-office.jpg |
| photo1.png | responsive-mobile-website.png |
Alt Text
Write descriptive alt text that explains what the image shows. Be specific and include relevant keywords naturally – but don't stuff them.
File Size and Format
Large images kill page speed. Compress images and use modern formats:
- WebP for most images (best compression)
- JPEG for photographs
- PNG for graphics needing transparency
- SVG for logos and icons
Dimensions
Serve images at the size they'll be displayed. Don't upload a 4000px image for a 400px display space.
Technical Considerations
Lazy Loading
Load images only when users scroll to them, improving initial page speed.
Responsive Images
Serve different sized images for different devices using srcset attributes.
Structured Data
Image schema markup can enhance how images appear in search results.
Image SEO Checklist
- Descriptive file name
- Compressed file size (aim for under 100KB for most images)
- Appropriate format
- Meaningful alt text
- Correct display dimensions
- Lazy loading enabled