Images are usually the heaviest part of a web page. This check finds the images slowing your WordPress site: files that aren't served in modern formats (WebP/AVIF), oversized or uncompressed images, images without lazy-loading, and images missing width/height that cause layout shift.
WPDoctor scans your page's images and reports the total payload plus which images to fix first for the biggest speed win.
On a typical WordPress page, images make up more than half of the total download size. That means image optimization is often the single biggest speed win available — bigger than tweaking scripts or caching. Yet most sites upload images straight from a phone or stock library at full resolution, serve them in old formats, and never lazy-load them.
This checker scans every image on your page and reports the total payload plus which images are dragging your load time down the most.
WebP and AVIF are modern image formats that compress dramatically better than JPEG or PNG — often 30–70% smaller at the same visible quality. Serving them is one of the easiest big wins for speed. Lazy-loading defers images that are below the fold until the visitor scrolls near them, so the initial page loads faster and uses less data.
Together, these two changes alone can transform a slow, image-heavy page. The report tells you which images to convert and where lazy-loading is missing.
Image problems don't just slow the page — they hurt your Core Web Vitals directly. A large hero image is often the Largest Contentful Paint element, so optimizing it improves LCP. Images without width and height cause layout shift, hurting CLS. And descriptive alt text helps both accessibility and image search rankings.
The full report ranks your images by potential savings and shows exactly how to fix each one, so you get the biggest speed and SEO improvement for the least effort.
Modern image formats that compress much better than JPEG/PNG at similar quality — often cutting image weight by 30–70%.
Deferring offscreen images until they're about to scroll into view, so the initial page loads faster. WordPress supports it natively.
Images without set width/height let the layout jump as they load, hurting your Cumulative Layout Shift score. Setting dimensions fixes it.
Often yes — image optimization plugins can auto-generate WebP/AVIF and compress uploads. The report explains your best options.
Done right, no visible difference. Modern formats like WebP and AVIF keep the same perceived quality at a fraction of the file size. The report flags images that are far larger than they need to be.
Serve images no larger than they're displayed, in WebP or AVIF, usually well under 200KB for most content images. Hero images can be larger but should still be compressed and preloaded.