Some images still use older formats instead of WebP or AVIF

WebP and AVIF are modern image formats that produce noticeably smaller file sizes than older formats like JPG and PNG for the same visual quality. This check measures what share of a site's images already use a modern format. On this site, coverage is partial: a meaningful share of images still use the older JPG/PNG formats. Each image still in an older format is an easy win left on the table for page loading speed, since every one of those images could be smaller without losing visible quality, and image weight is often the biggest single factor in how fast a page's main content appears. Your developer should identify the remaining legacy images, ideally by auditing per directory or page template, and convert them to WebP or AVIF as part of the build process. Use a picture element with a fallback so the small remaining share of older browsers still get a working image. Budget around a day for a full site pass.