Every current browser displays WebP, and so do WordPress, Shopify and most CMSs. It is the right format for website images. It is the wrong format for Instagram, Facebook and most upload forms, which convert it or reject it; for those use the JPG presets.
Quality behaves like JPEG: the tool searches for the highest quality under your cap. For screenshots and graphics with transparency, WebP output is often 5 to 10 times smaller than the PNG original.
Try it on your own photoDrop a photo at the top of the page. Ten seconds later it's sized, sharpened and ready to post.
Compress a photo