Recently I started to rewrite the core of a web app in Java (not including the Admin part). I have discussed ideas with colleagues and friends and one thing that seemed to be an agreement was that it is time to stop keeping the same image in two formats jpg or png or gif and in webp format. Not for this , but for other browser features like SharedWorkers support , WebSockets support e.t.c. I decided six months ago to put a tracker client side reporting back server side all this various technologies that the actual browser support , in some of our apps with rather heavy traffic . So I added the webp support expecting that the percentage of clients that don't support it is really low as the statics of the popular "can I use " suggest.

But the results are really weird to me , it seems between 7% and 15% of clients, depending on the app's audience, don't support WebP. In almost all of these cases, both client-side and server-side detection methods agree. It seems that the majority of them are in mobile in WebView or a similar technology.

I am writing about this because I found it extremely weird that something like this is happening but it is not reported (in my knowledge at least). I'm curious if anyone else has encountered similar issues or has real life data to confirm or refute this finding.