SEO & Discovery · · 10 min read
Written by Saleh S.
Google Images drives billions of searches every month, yet most sites treat images as an afterthought. Image SEO is about making every asset understandable to search engines - through filenames, alt text, format, and performance - so it earns visibility and referrals.
Use Descriptive, Keyword-Relevant Filenames
A file named IMG_4092.jpg tells Google nothing. Rename assets to describe the subject before uploading, using hyphens between words so crawlers can parse the text.
- Instead of photo1.jpg, use fresh-baked-sourdough-bread.jpg.
- Keep filenames concise and accurate; do not stuff every keyword into one name.
- When downloading many assets at once, batch-rename them with a naming template before publishing.
Write Meaningful Alt Text
Alt text is read by screen readers and search engines alike. Describe what the image shows in plain language and weave in context when it is natural - never keyword-stuff. Decorative images should use empty alt attributes so crawlers skip them.
Compress, Convert, and Load Images Correctly
File size and delivery directly influence Core Web Vitals, which Google weighs in rankings. Serve modern formats like WebP, resize images to their display dimensions, and add width and height attributes to prevent layout shifts.
- Use loading="lazy" for below-the-fold images and eager loading for the LCP image.
- Compress every asset to remove redundant metadata and imperceptible detail.
- Keep above-the-fold images under a reasonable byte budget so Largest Contentful Paint stays fast.
Add Image Structured Data
Marking up product and recipe images with ImageObject structured data can make eligible images appear with richer display in search results. Provide at least one high-resolution image (1200px or wider) that matches the page's core content.
Key Takeaways
Image SEO compounds: better filenames and alt text improve discoverability, while smaller, correctly-delivered files improve the speed signals Google rewards. Optimize your images once and they keep earning search traffic.