macOS seems to recognize WebP images as such, and seems like it actually tries to display previews of them, but always fails.
They are also associated with Preview application, just like other image formats, but Preview also chokes on it (without any error messages, it just silently fails to open a window).
Does it mean that it's intended to actually work but it fails just on my system for some reason?
In my case, the WebP images are lossless and not animated.
Best Answer
Now it's possible with this Quick Look plugin:
WebPQuickLook