I recently learned of Google's new WEBP format.  It is to replace  JPEG, PNG and GIF including animated GIF.  All browsers support it now.  I downloaded  the programs that support it.  I found it is still beta and many of the options just don't work.  However it compresses my animated GIFs to sizes 2% to 30% less.  Noting the Imagefap has a 12MB limit on the size of an upload, less is more. I tested uploading a WEBP animation but Imagefap rejects the format.  I asked them if there was any plans to support it in the future but they have more serious things to do, like keeping the servers from clogging.  As I said it is beta and considering they need to thumbnail all pix and strip out metadata it will be a while.