I would wonder what you are using for your image manipulation.. I am using an older version of GIMP and on maximum compression I got 6.33KB, on minimum I got 16.2KB, my high quality jpg came up both smaller and nicer than yours.. This is the 6.33KB PNG version.. http://i.imgur.com/8IETYdV.png imgur has also reduced the size of the jpg I uploaded(5.86kb) to 4.23KB and its http://i.imgur.com/s6Y49wws.jpg For JPG I got 625Bytes minimum quality and 5.86KB on maximum quality. 5.86KB version.. Check out this link, with all 4 files.. the only one that doesn't look good is the 625byte jpg, the other 3 all between 5.86KB and 16.2KB all look fine, too the point I cant really see a difference between my high and low quality PNGs and my High quality JPG. http://imgur.com/a/VMHHe PNG is a lossless image standard, unlike JPG which will compress imagers smaller but will lose quality, it has nothing to do with transparency in this image as it has no need for it, or shouldn't. If you have layered one image over another and turned on transparency then you are choosing to waste file size for no real reason. As for the reason on the limit, we have allowed larger avatars for official representatives such as Moderators and Squad team members so they can be clearly told apart, other issues may or maynot have to do with how VB handles avatars as opposed to sigs, avatars may have higher server overhead..