Compress a WebP image

The name WebP covers two ways of storing a picture. Lossy WebP works like JPEG with a newer engine: it predicts each block from its neighbours and stores only the difference, which is where the saving over JPEG comes from. Lossless WebP is closer to PNG and keeps every pixel. A file exported by a design tool can be either, and you cannot tell from the extension.

In Quality mode the output here is lossy, and the slider behaves much as it does for JPEG, with 75 to 85 a sensible range for photos. Switch to Lossless and the result is pixel-exact, which suits icons and interface graphics that were lossless to begin with.

An animated WebP keeps all of its frames when you compress it or scale it down, so stickers and short loops come back still moving. Cropping or rotating is different: those return the first frame only, and the result carries a warning so the change does not go unnoticed. Smart mode does not search on animations. It uses a fixed quality of 80, since comparing every frame with the original would take far longer than the saving is worth.

A WebP that was already saved at a low quality has little left to give. Encoding it again at a higher setting produces a bigger file, and encoding at the same setting loses detail for almost no gain. When the result would not be smaller than what you uploaded, you get your own file back, marked as already optimised, so a good file is never swapped for a worse one. To go further you have two honest options: fewer pixels, with Resize, or AVIF, which is in the Format menu and often undercuts WebP on photographs.