Google's John Mueller said on Twitter there is maybe a small bandwidth savings when it comes to GoogleBot crawling your site when you use webp over jpeg image formats. But then you would only see that difference when the site is a "very image-heavy site." So normal sites probably wouldn't really see any bandwidth savings there.
Here was the question:
when you have both jpeg/webp version of an image. Is there a benefit/downside to serve the WebP version to the crawler vs the more generic .jpg? #SEO #Images #WebP @JohnMu @Kevin_Indig
— Tim Vereecke (@TimVereecke) August 26, 2020
Kevin Indig and John Mueller responded similarly:
I think the primary difference you'd see is with regards to bandwidth needed for crawling (and probably that wouldn't be too massive unless it's a very image-heavy site, like Kevin mentioned). You shouldn't see any difference with regards to user-facing SEO.
— 🍌 John 🍌 (@JohnMu) August 26, 2020
John Mueller of Google added that you "shouldn't see any difference with regards to user-facing SEO."
Forum discussion at Twitter.