WebP is a modern image format developed by Google. It compresses photos and graphics more efficiently than JPG and PNG, so pages load faster and files take up less space — at the same visible quality. It also supports transparency, like PNG.
The downside: some older apps and workflows still don't recognise WebP, which is why people often convert it back to JPG or PNG.
You can convert to WebP to shrink files, or convert WebP back to JPG when you need wider compatibility.
How much smaller is WebP in practice
For photographs, lossy WebP typically lands 25-35% below a JPG of equivalent visual quality. For graphics with transparency, lossless WebP is usually around 20-25% smaller than PNG. On an image-heavy page those savings compound into a noticeably faster load, which is why WebP has become the default export format for most website tooling.
Two modes in one format
WebP is unusual in covering both jobs. Lossy WebP works like JPG, discarding detail to save space, and is the right choice for photographs. Lossless WebP works like PNG, reproducing every pixel exactly, and is right for logos, screenshots and line art. Unlike JPG, lossy WebP also supports transparency, which makes it the only common format that can do a soft-edged cut-out at photographic compression rates.
Compatibility today
Every browser released in roughly the last five years handles WebP, including Safari since version 14. The friction is no longer the web but everything around it: some desktop editors, older print workflows, certain upload forms and various phone galleries still refuse it. That mismatch is why converting WebP back to JPG or PNG is a more common need than converting to it.
Animation
WebP also supports animation and is substantially more efficient than GIF for the same clip. It never displaced GIF socially, largely because GIF was already universal in messaging and email, but for animation on your own website WebP is the better technical choice.