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PECompact version 2
Why not use the best?
Updated May 2004.

Intuitive GUI and console mode application allow for compression of entire projects or file masks, even directory recursion is supported:


[ Download the Trial Version ]
[ Purchase license now ]

PECompact v2 is a next generation win32 portable executable compressor. Runewritten from the ground up, PECompact v2 is designed to be the ultimate solution to executable compression. Some of its many advantages are:

  • Modules are typically compressed much tighter than modern data compression software can achieve due to optimizations made to modules before compression.

  • Compatible with EXE, SCR, DLL, OCX, and other Portable Executables. PECompact is the top compressor in its genre.

  • Console mode application that supports wildcards and directory recursion included.

  • Supports third party CODECs.

  • Supports custom loaders (decompression stubs - the code attached to compressed modules).

  • Fully tested under all win32 flavors for proper handling of all conditions, including base collisions.

  • Compatible with Data Execution Protection (DEP) on AMD 64bit platforms running Windows XP SP2 or other operating systems.

  • Compressed modules resist tampering and reverse engineering.

  • Decompression and reconstruction at runtime is faster than competing products.

  • Includes Jørgen Ibsen's CRC32 (integrity check) CODEC.

  • Includes Jørgen Ibsen's encryption (password) CODEC.

  • Includes Anti-debug loader (retail/registered build only).



Compression results in a substantially smaller module, on average 60-70% smaller! PECompact compresses modules tighter than if they had been compressed by any other executable packer or modern data compression software. This is achieved by advanced pre-processing and state of the art CODECs.

Before compression:




Data must be retrieved from the storage medium in its bloated, uncompressed form.


After compression:


Compressed data

Uncompressed data


Module runs exactly as before and there is much less data to be retrieved from the storage medium.

Choosing the right executable packer can make a huge difference!

Adobe Acrobat Reader 6.0 executable compression benchmark.
Original file size: 7,671,876
File date: 11/03/03

Compressor Settings

New size

PECompact v2.10 LZMA codec, small decoder, slim loader


PECompact v2.10 LZMA codec


UPX v1.24w --best 2,908,160
PECompact v2.10 Default. (FFCE codec, fast decoder) 2,934,272
UPX v1.24w Default. 2,955,264
ASPack v2.12 Default


CExe v1.0b Default 3,904,512
PEPack v1.0 Default 3,735,552
FSG v1.33 Default. 4,031,456
WWPack32 v1.20 Default 4,221,952
EZIP v1.0 Default. 5,985,427
PETITE v2.2 Default. Error. Could not compress.

Try the test for yourself on your own executable and modules. A benchmark conducted by a third party with an executable selected prior to PECompact2's creation is here.

Why choose PECompact?

  • PECompact is the top performer in compression.

  • PECompact has been thoroughly tested under all win32 variants.

  • PECompact is up to date.

  • PECompact is the most configurable executable packer in existence.

  • Bitsum Technologies cares about performance.

  • You know you will be supported by the author.

  • If you are looking for anti-virus software interoperability: Bitsum Technologies has worked with a large number of anti-virus vendors to ensure that they can scan inside compressed modules and that compressed modules are not flagged as viruses. In addition, we design our products to avoid false detection as viruses by unknown anti-virus software.

Why purchase a PECompact license?

  • Licensed users have distribution rights for compressed modules.

  • Licensed users receive special CODEC and Loader plug-ins for increased security and functionality.

  • Licensed users can download any public version released from an easy to use download center.

  • Licensed users receive priority support.

  • Licensed users support future PECompact development.

I use PECompact to protect my executables, why shouldn't I use a product designed specifically for this?

  • Many executable protectors are not supported by many anti-virus softwares. This causes false alarms and other problems.

  • Many executable protectors do not offer full compatibility with DEP (data execution protection) features of 64bit AMD processors.

  • PECompact supports Loader plugins, allowing for use of either pre-supplied protection loaders or customized protection loaders that are inherently infinitely more secure than shrinkwrapped, all-purpose protection.

To order please see the purchasing page.

PECompact documentation is browsable online

Latest build: 2.10

[ Download the trial version ]
[ Purchase license now ]

Please read about the various license types on the PECompact Ordering page.
A freeware license is available for only a $3 processing fee. It offers limited distribution rights of compressed modules. Read about this license type here.

Development Acknowledgements:

  • Jørgen Ibsen has contributed his FFCE, aPLib, and BriefLZ compression CODECs, password encryption CODEC, CRC32 integrity test CODEC. We thank him for his support and contributions. Visit his site at for lots of good software.
  • A variety of users have contributed their ideas and bug reports. We thank you.

Student/Freeware Licensed Version:

! Remember ! Modules compressed by the student/freeware licensed version may not be transferred in any way in exchange for money or other goods or services.
Students and Freeware Authors: Download (freeware license) - We prefer you register by purchasing the $3 freeware license, but this build is for those of you who can't or don't want to.