WebP files: why the web serves them and your software will not open them

Where WebP came from, what it does better than JPG and PNG, and how to convert one when a tool refuses it. Convert WebP in your browser, no upload.

At a glance

Type: Image
Extensions: .webp
MIME type: image/webp

WebP came out of Google in 2010, built from the intra-frame coding of the VP8 video codec — compressing a still image with the machinery designed for a single video keyframe. The result does what previously took two formats: lossy compression roughly 25–30% better than JPEG, a lossless mode that beats PNG, an alpha channel, and animation. One format covering everything the web needed.

That is why sites serve it and why you keep ending up with files you cannot open. The support gap is not in browsers — Chrome, Firefox, Safari and Edge have all read WebP for years — it is in everything else. Image editors were slow, print workflows never bothered, office suites lag, older phones cannot, and upload forms written a decade ago reject the extension outright. Right-clicking an image on a modern site and getting a .webp your software will not touch is now an ordinary experience.

Converting out of WebP is therefore the common direction, and the choice of target follows from the content. JPG for photographs where the file has to be small and universally readable. PNG when the image has transparency or you are about to edit it. Both are second-generation encodes if the WebP was lossy — which most on the web are — so convert from the largest version you can get rather than a thumbnail.

Converting into WebP is worth doing for anything you serve yourself. A PNG of flat graphics can shrink by ten or twenty times with transparency intact; in one test here a 76 KB PNG became a 3.5 KB WebP. Note that this site's WebP output is lossy at the default quality — your browser's encoder is doing the work, and it makes the same bargain JPEG does.

Convert WebP to other formats

Convert other formats to WebP

FAQ

Why can my software not open WebP?

Because support outside browsers came late and unevenly. Older image editors, print workflows, office suites and many upload forms still reject it, even though every current browser reads it.

Should I convert WebP to JPG or PNG?

JPG for photographs that need to be small and open anywhere. PNG when the image has transparency or you are about to edit it, since PNG stops any further loss.

Is WebP better than JPG?

Yes, by roughly 25–30% at comparable visible quality, and it also supports transparency and animation, which JPEG does not. Its only weakness is software support outside the browser.

Does WebP support transparency?

Yes, a full alpha channel — that is a large part of why it can replace both JPEG and PNG. Converting a transparent PNG to WebP keeps the transparency.

Is WebP lossy or lossless?

It has both modes. Most WebP files on the web are lossy. This site's WebP output is lossy at the default quality of 82, since it uses your browser's own encoder.

What about animated WebP?

The format supports animation, but converting one to a still format here writes only the first frame. Convert to GIF or MP4 if you need the movement.

Will the JPG be bigger than the WebP?

Usually yes, and that is expected. WebP is the more efficient format, so matching its quality in JPG takes more bytes. You are converting for compatibility, not for size.

Does converting here upload the image?

No. Your browser contains both a WebP decoder and encoder, so the work happens in the page with nothing downloaded and nothing sent.