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Chinese (simplified), English, Italian, Japanese, Polish, Russian, Slovenian
Windows XP, Vista, 7, 8, 10, 11



FUPX is an advanced graphical interface for the UPX (Ultimate Packer for eXecutables).

It allows you to compress (and decompress) files produced according to Microsoft Portable Executable Specification (EXEDLLOCX, BPL, CPL and other), ELF executables, Mac OS X executable files (Mach-O, Mach-FAT) and other. It offers easy access to all documented and undocumented UPX parameters without the need for command line usage.

The FUPX interface is very simple and user-friendly. To compress executable files, just drag & drop them into main window, select proper profile from list, and click the button.

FUPX works with the last six versions of the UPX: 3.91, 3.92, 3.93, 3.94, 3.95, 3.96 and 4.0.0. The active UPX version can be set in the program options.

Current version supports 64-bit executable files (Win64/PE), but this feature is declared as experimental.


The most important features

  • Compression and decompression of executable files: Windows Portable Executable files (EXE, DLL, OCX, BPL, CPL, SYS, AX, ACM, DRV, TLB and other), ELF executables (used on Unix, Linux, Solaris, FreeBSD and other operating systems), Mac OS X executables (Mach-O, Mach-FAT) and other.
  • Easy acces to all UPX command-line parameters.
  • Displaying detailed informations about compressed files: original file size, compresson ratio, saved space, compression level and other.
  • The ability to filter files based on multiple criteria.
  • Predefined UPX profiles for beginners. Advanced users can define custom profiles.
  • Portability. FUPX does not use system registry and all settings are stored in INI file, so it can be run from portable drives.
  • Shell integration (optional).
  • 100% freeware! – for private and commercial use. There are no limitations, adware, spyware.

How to uninstall?

If you no longer use FUPX application or if you want to free up space on your hard disk, you can uninstall this program from your computer. To do this, follow these steps:
  1. Open Programs and Features by clicking the button, clicking Control Panel, clicking Programs, and then clicking Programs and Features.
  2. On the list of installed programs select FUPX and then click Uninstall. This will launch the uninstall wizard.
  3. Follow the instructions displayed on the screen.

End User License Agreement

This program is completely free. You can use it without any restrictions, also for commercial purposes.


Version 3.2 (2022.11.09)

  • Support for the latest UPX version – 4.0.0.
  • Several bug fixes and improvements.

Version 3.1 (2020.05.14)

  • Support for the latest UPX version – 3.96.
  • From now on, the user can configure the program to work with any version of UPX. To do this, add the appropriate entries to the “upx\upx.ini” file.
  • Added mechanism to support multiple languages based on INI files.
  • Many small improvements.

Version 3.0 (2019.09.22)

  • The program’s main window has been almost completely redesigned. All controls for controlling UPX settings have been placed on the panel visible on the right side of the main window. In addition, for easier navigation, they were divided into categories and placed on smaller foldable panels.
  • From now the program is also available in a 64-bit version.
  • The information module has been significantly expanded. Now, detailed information about PE (Portable Executable), ELF, Mach-O and Mach-Fat executable files is displayed.
  • New columns: Icon, Full file name, OS (operating system).
  • File list toolbar has been added.
  • Added option to skip compressing individual files in the window with compression progress.
  • Added option to reload the file list.
  • A module checking availability of program updates has been added.
  • New About window displaying additional information.
  • Many minor changes and improvements.

Version 2.5 (2018.09.18)

  • Program name was changed from Free UPX to FUPX.
  • Added support for the latest version of the UPX: 3.95 (32-bit and 64-bit).
  • New module: File info.
  • The ability to check the selected executable file on the site has been added.

Version 2.4 (2017.05.13)

  • Added support for the latest version of the UPX: 3.94.

Version 2.3 (2017.02.17)

  • Added support for the latest version of the UPX: 3.93.

Version 2.2 (2017.01.11)

  • Added support for the latest version of the UPX: 3.92.
  • Added possibility to choose the active version of the UPX: 3.91 or 3.92.
  • New compression profile: Best compression / LZMA.
  • Minor modifications to the source code and user interface.

Version 2.1 (2016.09.23)

  • Minor modifications to the user interface.
  • New action: Clear file list.
  • Minor bug fixes and enhancements.

Version 2.0 (2016.05.26)

  • Major modifications to the user interface.
  • Displaying additional information about executable files.
  • The ability to filter files based on multiple criteria.
  • Changed toolbar.
  • New icons.
  • New file list control with many additional features (sorting, row and column moving…).

Version 1.7 (2013.10.07)

  • New version of the UPX (3.91w).

Version 1.6 (2013.03.12)

  • New version of the UPX (3.09w).
  • Minor modifications to source code related to the program adjustment to support the new version of UPX

Version 1.5 (2011.12.15)

  • New version of the UPX (3.08w).
  • Minor modifications to source code related to the program adjustment to support the new version of UPX

Version 1.4 (2010.09.16)

Version 1.3 (2010.05.07)

  • New version of the UPX (3.05).

Version 1.2 (2009.10.28)

  • New version of the UPX (3.04).
  • Support for XP visual styles.

Version 1.1 (2008.07.01)

  • New version of the UPX (3.03).
  • Small source code modification.

Version 1.0 (2008.04.01)
Initial release.

Previous versions

FUPX 3.1 / UPX 3 (91, 92, 93, 94, 95, 96) 64-bit
Release date: 2020.05.14
File size: 6.1 MB
SHA-256 checksum: e51c8077980a625422663e8cf8052cc91585ba5a91d30acc57873d7695329fe4
FUPX 3.1 / UPX 3 (91, 92, 93, 94, 95, 96) 32-bit
Release date: 2020.05.14
File size: 5.4 MB
SHA-256 checksum: 91b1ad50b50e68ab4529ad3113364f0824acc537547bb545bb74d0ae0f813a8d
FUPX 3.0 / UPX 3 (91, 92, 93, 94, 95) 64-bit
Release date: 2019.09.22
File size: 5.2 MB
SHA-256 checksum: de08102eceadcc968245c177cf9ef50dfab6288ae14b401d9c67367f57dd907d
FUPX 3.0 / UPX 3 (91, 92, 93, 94, 95) 32-bit
Release date: 2019.09.22
File size: 4.5 MB
SHA-256 checksum: ee9269857da3ba8484603ee17f19da9448a0529de16404588cad49d8c7517fdf
FUPX 2.5 / UPX 3.91, 3.92, 3.93, 3.94, 3.95 32-bit
Release date: 2018.09.18
File size: 3.7 MB
SHA-256 checksum: 74ef2df09d6c5563a19d95eb2554176bbaaa7052213e7dbafc8984b7bf46a257
Free UPX 2.4 / UPX 3.91, 3.92, 3.93, 3.94 32-bit
Release date: 2017.05.13
File size: 2.4 MB
SHA-256 checksum: c0b6fe8ecabfb41a568fecb24b48d393f2e9952b3fe6c7264699ed680ee027de
Free UPX 2.3 / UPX 3.91, 3.92, 3.93 32-bit
Release date: 2017.02.17
File size: 2.0 MB
SHA-256 checksum: 6a0e2ff3f8207c72bfc976ad78038e13ba63ec0d06bd3f11116753f7db3e0267
Free UPX 2.2 / UPX 3.91, 3.92 32-bit
Release date: 2017.01.11
File size: 1.7 MB
SHA-256 checksum: c9662cdc48ba69da8779913a5bd20823e8515fa257def3d6b2721a11bd73e53d
Free UPX 2.1 / UPX 3.91 32-bit
Release date: 2016.09.23
File size: 1.3 MB
SHA-256 checksum: b1ad000f66489fcf5043693beb3d2f6edee9bc438075d0631a1d9c061ff7b5fb
Free UPX 2.0 / UPX 3.91 32-bit
Release date: 2016.05.26
File size: 1.4 MB
SHA-256 checksum: 73f31fa932bbb2f3f5284aaa8c5df33c5492d1009453e4d5c6b8c13d8a8e2d7f
Free UPX 1.7 / UPX 3.91 32-bit
Release date: 2013.10.07
File size: 646.1 KB
SHA-256 checksum: ad035464e1d8154c574ff839683a0f79885030c413ebcb26281e56ff57ac0103
Free UPX 1.6 / UPX 3.09 32-bit
Release date: 2013.03.12
File size: 610.0 KB
SHA-256 checksum: 13c293d56894fd4e758183e97079d7c947e9e289324ba70fb2c843a99abbe0cf
Free UPX 1.5 / UPX 3.08 32-bit
Release date: 2011.12.15
File size: 608.0 KB
SHA-256 checksum: ba78b30501783560950172cbe7c9c8bc0fb93aeee4612029cb63ab438cc7af0e
Free UPX 1.4 / UPX 3.07 32-bit
Release date: 2010.09.15
File size: 604.7 KB
SHA-256 checksum: e964784bb314113dd9e7cbc53468c8203f254e3cc9981f15787f6c123c1851fa
Free UPX 1.3 / UPX 3.05 32-bit
Release date: 2010.05.07
File size: 603.7 KB
SHA-256 checksum: 05011bc9f9d6d464e292a8f56e4a2c26f5387c64cb5127bc5ace7d361fca4227
Free UPX 1.2 / UPX 3.04 32-bit
Release date: 2008.08.28
File size: 597.7 KB
SHA-256 checksum: eb91332d655da464de5dbe93316628c0650cec8b50c540e751f95a794e3c7e28
Free UPX 1.1 / UPX 3.03 32-bit
Release date: 2008.07.01
File size: 579.9 KB
SHA-256 checksum: 57feb17ff34cb7d110bdc704fd416de99da0e83715ef9f2df0e425e46bbf892f
Free UPX 1.0 / UPX 3.02 32-bit
Release date: 2008.04.01
File size: 583.6 KB
SHA-256 checksum: 41658c46f7d36b3bd3775cf13fb191b4c39fdd69e9538e81cb4e96f9268636a9