Moved from post #315296:

Jennifer003b said:
The weird thing is...WebP is a free format and it's right now (not tomorrow, not in a year) supported by ALL major browsers (see ) so the only "excuse" not to use it it's because someone wants to pay more for his server's bandwidth (or doesn't want to bother to update the site) which is perfectly fine by me I don't pay my internet connection based on how much I use it so...
If it's not supported already, it probably won't be. The owner doesn't have anyone they allow to work on the site code. We use a fork of Moebooru and they haven't been willing to make it public.

And as I mentioned, using a webp as wallpaper without recompression might not be possible either.

I don't think pixiv supports webp either. If they do, it's certainly not common to find any there. So it's not like we're forcing contributors to convert any significant number of images just to upload here.

There's certainly no problem with supporting it. It's just not likely to happen.