It supports hd skins, jpg skins, new format skins for input. The output skin will always be of the same format as shown in the example. Warning! The definition of slim skins may be inaccurate due to ...

SkinsRestorer allows players and admins to apply custom skins. Skins are basically just 64x64 PNG images stored on the Minecraft CDN and signed via the yggdrasil private key. Confused what that means?