TL;DR
Image optimization is the practice of serving images at the appropriate dimensions, compression level, and format (such as WebP or AVIF) for the requesting device, often through the <picture> element, srcset, and sizes attributes.
What is Image Optimization (WebP / AVIF / Responsive Images)?
Image optimization is the practice of serving images at the appropriate dimensions, compression level, and format (such as WebP or AVIF) for the requesting device, often through the <picture> element, srcset, and sizes attributes.
Learn more in our how to improve image optimization guide, or work with us through our done-for-you speed optimization service.
How WebP / AVIF / Responsive Images is Measured
PageSpeed Insights audits include 'Properly size images', 'Serve images in next-gen formats', and 'Efficiently encode images'.