How to Optimize Images for SEO (Complete Guide)

How to Optimize Images for SEO (Complete Guide) Images make up roughly 50% of a typical web page's total weight. Get image optimization wrong, and you tank your Core Web Vitals, frustrate visitors, and hand rankings to competitors who got it right. This guide walks through exactly how to optimize images for SEO — from choosing the right format to writing alt text that actually helps you rank. Every step here is actionable. No theory without application. Why Image SEO Matters Three reasons image optimization deserves serious attention: Page speed directly affects rankings. Google's Core Web Vitals — specifically Largest Contentful Paint (LCP) and Cumulative Layout Shift (CLS) — are ranking signals. The largest element on most pages is an image. An unoptimized hero image that takes 4 seconds to load pushes your LCP past Google's 2.5-second threshold and kills your ranking potential. CLS suffers too when images load without defined dimensions, shoving content around as the page renders. G