

While that is not a big issue, since most modern image viewers support the webp format by now, it is still something that you may not like that much, depending on what you do with the images.

The websites in question check the browser you are connecting with and either deliver webp if supported, or fall back to jpg or png if it is not. If you are running Chrome, you get webp images exclusively on those websites, while Firefox or Internet Explorer users get the standard image formats instead. It reduces the file size in comparison to png images by up to 26%, and by up to 34% in comparison to jpg images.

Google claims that webp reduces the size of images significantly in comparison to png and jpg.
