Should my website use WebP instead of JPEG?
Yes, for almost every photo. WebP and AVIF are modern image formats that are around thirty per cent smaller than JPEG or PNG at the same visible quality. Every modern browser supports WebP, and smaller images mean faster pages, particularly on phones. Most platforms can convert on upload, so it costs nothing to switch.
Why it matters
Images are usually more than half of a page's weight, so a thirty per cent saving on images is a large saving on the whole page. A gallery page with twenty 300 KB JPEGs becomes twenty 200 KB WebPs and loads two seconds sooner on 4G. Google's PageSpeed Insights lists "Serve images in next-gen formats" on nearly every site that has not switched.
WebP or AVIF?
AVIF is newer and smaller again, often half the size of a JPEG, but it takes longer to encode and older browsers do not show it. The safe approach is WebP for everything, with AVIF where your platform can serve it and fall back automatically. PNG still has a place for logos and graphics that need sharp edges and transparency, though WebP handles transparency too.
How to check
Our check looks at the file extensions of the images on your home page and reports how many are JPEG or PNG. PageSpeed Insights estimates the saving available.
How to fix it
On WordPress, an image optimisation plugin converts new and existing uploads to WebP and serves them where supported, with no change to the pages. WordPress itself can save WebP copies on upload. If you use a content delivery network with image optimisation, it converts on the fly. For a hand-built site, export from your image editor as WebP and use the picture element to offer a JPEG fallback.
Not sure how your own site does on this? Run the free check: it takes about twenty seconds and reports on this and thirty other things.