While on Linux converting a pile jpegs to WebP is not a problem, for some reason it doesn’t seem possible yet to do it on Windows with cwebp. That’s okay because Цветелин Новкиришки (not sure about the pronunciation, though also known as metal03326..) came to the rescue with MultiWebP which lets you convert huge directories with a couple right clicks. How? With a nostalgic DOS-ish .bat file, you right click your folder of interest > Send To > MultiWebP, go for a walk, and presto. If you’d like you can tweak the .bat for cwebp options including quality levels, lossless, auto filter and so forth.
Though a tad tricky to rig up at first, you can pull it off if you follow his steps and grab MultiWebP from his website. I profusely recommend it if you have any interest in this fantastic image format, or for anyone who really loves … pictures but is tight on space. When was the last time you used a .bat file (that had a happy ending)?