Checks if images use responsive techniques like srcset.
Responsive images are techniques (like the `srcset` attribute) that allow you to provide multiple versions of an image for the browser to choose from, depending on the user's screen size and resolution.
It prevents a small mobile device from having to download a massive desktop-sized image. This dramatically improves page load speed on mobile, saves user data, and improves user experience.
Not using responsive images can make your site very slow on mobile devices, which is a major negative ranking factor and a cause of high bounce rates.
<img src="small.jpg"
srcset="medium.jpg 1000w, large.jpg 2000w"
sizes="(max-width: 600px) 480px, 800px"
alt="A responsive image">Run a free audit to see how your site performs on Responsive Images and 159 other checks.
Start Free AuditChecks 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.
Checks if GZIP or Brotli compression is enabled.