You are here AppCompactor

App compressor

Download from

Version 3.7.1 for Windows, English
2MB download / 5MB installed
Notes | Antivirus Scan | Details

Runs anywhere (cloud, removable, local) without 'installing'. Use the Platform for easy installs and automatic updates.

Make a Donation - Support development & hosting

Description AppCompactor allows you to easily compress application to decrease size on disk and increase performance when running from a slow media (like flash drives). It features:

  • Proven UPX binary compressor
  • 7-Zip compression of archives
  • Multiple compression levels
  • Automatic testing of compressed files
  • Automatically skips <4K files (no space savings)
  • Add inclusions/exclusions using Format
  • Compression of DLL, EXE, ZIP, JAR, IRC, PYD and BINs in all directories
  • Automatically skip launcher if selecting Format apps' base directory
  • Automatically excludes Visual C++ runtimes and Qt image handlers
  • Saving up to 50% or more installed space of many apps
  • Faster application starts from flash drives
  • The same technology we formerly used in Portable, Pidgin Portable, GIMP Portable and more!

Please mention us and link back here if you use our AppCompactor in your releases as a way of saying thanks. We appreciate it!

App Notes

Deprecated: We've deprecated use of the AppCompactor for official releases due to issues around false positives and bugs within apps. You can still use it with your own apps, though.

Helpful tips:
  • Don't compress NSIS launchers (FirefoxPortable.exe, etc), they'll break
  • It's best to have the app you're compressing reside on a hard drive (at least temporarily) rather than a flash drive to improve performance and decrease writes to your flash drive
  • You can disable the Welcome screen or have the console window stay by editing the settings.ini in the Data directory
  • NRV2E is recommended as it is the least likely to break things in our testing
  • Always back up your files before using this tool as it will not work with all applications.

False Positive Note: The current UPX 64-bit binary has false positives in a handful of antivirus engines. We've reported the issue to them. EXEs and DLLs compressed with UPX are more likely to trigger false positives in antivirus apps.

HowTo: The AppCompactor.ini can reside in the AppInfo directory alongside the AppInfo.ini and Installer.ini. An example of the file follows:


Within the [PortableApps.comAppCompactor] section:

FilesExcluded are any files you would like excluded from an AppCompactor run separated by pipes |.

Note that the files listed in the example are excluded by default (Visual C++ runtime 9.0) as well as the 7.1, 8.0, and 10.0 versions of the same files.

AdditionalExtensionsExcluded is any additional types of files (extensions) that you would like to exclude from the compaction separated by pipes |.

AdditionalExtensionsIncluded is any additional types of files (extensions) that you would like to include in the compaction separated by pipes |.

CompressionFileSizeCutOff is the cutoff point at which to ignore files for compression in bytes. The default is 4096, meaning files 4K in size and smaller are ignored.


For help with this app, please see the following:

Download Details

Open Source Initiative
  • Publisher:
  • Date Updated: 2022-07-17
  • Date Added: 2008-03-20
  • System Requirements: Windows XP, Vista, 7, 8, 10, 11 & WINE
  • App License: Open Source (GPL)
  • Source: UPX, 7-Zip, Launcher source included, Installer
  • SHA256 Hash: 52423522e49869bf186ec11dd3db9d6e306734625d88aee29ebd4c65dd84191e AppCompactor is a trademark of Rare Ideas, LLC