[izacus]

WebP is mostly handled via transparent proxies - meaning people with proper browsers and Android mobile devices get WebP (large market share), everyone else gets (larger) PNGs.

That way you don't really care either way on the backend.

[JohnTHaller]

Saying 'proper browsers' gives away your bias there, since only the Blink WebKit engine supports it (Chrome/New Opera), which is under 20% of the desktop market worldwide.

[cbhl]

Saying 'desktop market' gives away your bias there too.