Like it or not, Google’s open source WebP image format is here to stay. At this point, the only thing holding back widespread adoption on the Internet is browser support. At present, the format is supported in Chrome, Opera, Opera Mini, Android Browser and Chrome for Android. However, with the folks at Mozilla working fast and furious to improve the Firefox experience in hopes of giving Chrome some competition, you can bet that Firefox support for WebP will be coming soon. When that happens, the two other major holdouts, Internet Explorer (now Microsoft Edge) and Safari, will be sure to follow suit.
When all browsers are on board, it’s certain that high traffic websites will adopt WebP as their graphics format of choice. Google is already converting most if not all graphics uploaded to Google+ to WebP to deliver to browsers supporting the format.