> It's a low-res JPEG with a fixed header to save a bit more space. This is also used to blur sensitive images. You can get even better results with webp. That

> It's a low-res JPEG with a fixed header to save a bit more space. This is also used to blur sensitive images. You can get even better results with webp. That is not my experience at all. On images less than 100kb, webp adds an overhead, and doesn't reduce the file size at all. A fixed header is also harder to achieve.