Compares delivered dimensions against rendered size for optimization opportunities.
Detects if images are being served at a much higher resolution than they are actually displayed at (e.g., serving a 4000px image inside a 300px box).
Serving oversized images wastes bandwidth and severely impacts Largest Contentful Paint (LCP).
Properly sizing images before serving them drastically improves page speed on mobile devices.
Run a free audit to see how your site performs on Image Compression Quality Check 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.