How to do image SEO

Image SEO starts with file optimization before upload. Rename your image files to be descriptive and keyword-relevant instead of keeping generic names like "IMG_2847.jpg" — use formats like "blue-widget-product-photo.jpg" that actually describe what's in the image. Compress file sizes aggressively using tools like TinyPNG or ImageOptim because page speed is a ranking factor and oversized images tank performance. Most agencies find that compressing images by 60-70% without noticeable quality loss is standard. Use modern formats like WebP when your CMS supports it, as these reduce file sizes another 25-35% compared to JPEG. For client sites, implement lazy loading so images don't load until users scroll near them, which improves Core Web Vitals scores that Google uses for ranking.

The alt text is where most SEO value lives. Write descriptive alt text that explains what's actually in the image while incorporating your target keyword naturally — "luxury leather office chairs in walnut finish" works better than "office chair" or keyword stuffing like "best leather office chairs luxury furniture modern design." Alt text should be 8-12 words typically, informative enough that someone who can't see the image understands its purpose. This helps both accessibility and search engine understanding. Title tags and captions add supplementary value but alt text is the priority. For image-heavy pages like product galleries or portfolio sites, having unique, relevant alt text on 80% of images noticeably improves organic performance.

Context matters as much as the image itself. Use images strategically on pages targeting specific keywords rather than adding generic stock photos everywhere. A product page about "ceramic tile installation" performs better when you actually show installation photos with relevant alt text than when you use random decorative images. Image file names, alt text, surrounding page copy, and the image's subject matter all work together in Google's assessment. Schema markup for images, particularly for product images using schema.org markup, helps Google understand and display images in rich results. For agencies managing multiple client sites, creating an image optimization checklist covering file naming, compression, alt text standards, and lazy loading implementation ensures consistency and prevents oversights that drag down rankings.