Extended image audit: HTTP vs HTTPS images, dimensions for CLS, lazy loading, and srcset usage.
This is an extended image audit that goes beyond basic alt text checks. It looks for images loaded over insecure HTTP on an HTTPS page (which triggers mixed content warnings), checks whether images have explicit width and height attributes (to prevent the page layout from jumping as images load), verifies that lazy loading is properly implemented for images that are below the fold, and checks if responsive 'srcset' attributes are used to serve appropriately sized images to different devices.
Images are often the heaviest resources on a web page and one of the biggest sources of performance and SEO issues. Missing width and height dimensions cause the page layout to shift as images load (hurting your CLS score), HTTP images on HTTPS pages trigger browser security warnings, and serving oversized images to mobile devices wastes bandwidth and makes everything slower.
Image-related issues directly affect Core Web Vitals — particularly Cumulative Layout Shift (CLS) and Largest Contentful Paint (LCP), both of which are confirmed Google ranking factors. HTTP images on HTTPS pages also trigger mixed content warnings that can scare visitors away from your site.
Run a free audit to see how your site performs on Image SEO (Extended) and 159 other checks.
Start Free AuditChecks if images use responsive techniques like srcset.
Checks if images have width and height attributes to prevent layout shift.
Checks for JavaScript errors in the browser console. (Note: In-dev check)
Measures the total size of the HTML document.