There's also a second option — adaptive posterization — that reduces PNGs by ~30%. Useful for images that are too "colorful" for 256-color RGBA.
WebP is a fine format, but establishing a new format on the web is really hard. There's a graveyard of better JPEGs, and after 16 years since PNG was published, GIF is still alive and well. http://ycombinator.com/images/y18.gif
The web has strong preference for "good enough that works everywhere". IE6 was enough to discourage devs from using PNG, nad you won't see Google's WebP in IE or iOS anytime soon.
Nowdays you can decode WebP with JS, but size of a JS decoder and CPU time to run it will most often offset any savings from the format.
WebP is a fine format, but establishing a new format on the web is really hard. There's a graveyard of better JPEGs, and after 16 years since PNG was published, GIF is still alive and well. http://ycombinator.com/images/y18.gif
The web has strong preference for "good enough that works everywhere". IE6 was enough to discourage devs from using PNG, nad you won't see Google's WebP in IE or iOS anytime soon.
Nowdays you can decode WebP with JS, but size of a JS decoder and CPU time to run it will most often offset any savings from the format.