What is WebP, and why are web images all WebP now?
You may have noticed that saving an image from a web page often gives you a .webp file that will not open on a double-click. This explains what WebP is, why it is increasingly common, and what to do when one will not open.
Where WebP came from and why it is good
WebP is an image format from Google, designed to make images smaller while keeping quality. At a comparable look it is typically 25–35% smaller than JPG, much smaller than PNG, and it supports transparency and animation. For a website, smaller images mean faster loading and less bandwidth, which is why most sites now use it.
Why it will not open
WebP is well supported in browsers — Chrome, Edge, Firefox, and Safari 14+ are all fine. But the world outside the browser has not fully caught up: some older Windows photo viewers, older Office versions, and certain print shop systems and upload forms still do not recognise it. So a WebP you save from a page will not open, or gets rejected, in those places.
The fix is simple: convert it to JPG (when you do not need transparency) or PNG (when you do). Conversion runs locally in your browser, with no upload.
Should you use WebP on your own site
If you build websites, WebP is worth using — smaller images directly improve loading speed and PageSpeed scores. Use the HTML picture element to offer both WebP and the original format so the few unsupported clients fall back automatically. But note: for images users will download (assets you want people to save), it is best to also provide a JPG, so they do not end up with a file they cannot open.
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