You offer two versions: * A webp version with transparency, which won't be supported by most clients but the ones which do will support everything * A JPEG ve

You offer two versions: * A webp version with transparency, which won't be supported by most clients but the ones which do will support everything * A JPEG version without transparency, or with "faked" transparency (i.e. baked-in background color), which will be supported by basically everyone but with less quality. That way, if the client is capable of loading the "good" version it will, and if it can't then it will load the "good enough" version.