Why Image SEO Matters in 2026
Images are often the heaviest elements on a webpage. If they are not optimized, they destroy your Core Web Vitals—specifically **LCP** (Largest Contentful Paint) and **CLS** (Cumulative Layout Shift).
1. The CLS Killer: Missing Width/Height
If an image lacks width and height attributes, the browser doesn't know how much space to reserve for it. When the image finally loads, the content jumps around (layout shift). This is a direct Google ranking penalty.
2. The Accessibility & SEO Requirement: Alt Text
The alt attribute provides a text description of the image. Screen readers use it for the visually impaired, and Google uses it to understand the image content for Google Images search.
3. The Speed Factor: Lazy Loading
Only the images "above the fold" (visible on first load) should load immediately. All other images should have loading="lazy" to defer loading until the user scrolls down, drastically improving initial page load speed.