UPX is a command-line device that allows you decrease the dimension both EXEs and DLLs UPX is a command-line device that allows you decrease the dimension both EXEs and DLLs, enabling more applications to be loaded onto a USB generate. It performs for DOS applications, and DLL’s.No extra application is needed for the compacted EXEs or DLLs to perform. An extra is a possibly quicker running system due to fewer study periods to fill the EXEs/DLLs.It contains UPX versions and it is able to constrict with LZMA (a better computer file pressure format).UPX Tool is absolutely more convenient and portable.