Ultimate executable compression tool

UPX (Ultimate Packer for eXecutables) is a free, open-source software designed to compress executable files efficiently without affecting their functionality. It reduces the size of programs and libraries, making them easier to distribute and store while preserving the original execution speed and behavior. It supports multiple platforms and file formats.

UPX is widely used by developers who need to minimize file sizes for portable applications or embedded systems. It achieves high compression ratios and quick decompression times, ensuring that executables remain lightweight yet fully functional. As a mature and reliable tool, it has become a standard choice in the software development community.

Powerful, versatile, and developer-friendly tool

UPX provides exceptional compression capabilities for executables across various operating systems. It supports numerous file formats such as PE, ELF, and Mach-O, allowing developers to work flexibly across platforms. The compression and decompression processes are remarkably fast, saving time during software deployment and execution. However, the program lacks a graphical user interface, which can discourage less technical users, and some antivirus programs occasionally flag compressed files as suspicious, causing inconvenience.

Its command-line interface is efficient and provides direct control, making it useful for experienced developers. However, it can deter beginners unfamiliar with text-based operations. Additionally, advanced usage requires a deeper level of technical knowledge, which can limit accessibility for casual users seeking a more straightforward compression solution. The software maintains binary integrity while reducing size, ensuring no runtime dependencies or performance penalties occur after compression. 

Alternatives include tools such as ASPack, MPRESS, and Petite, which offer similar functionality but often come with restrictions or limited support. However, this program stands out due to its open-source nature, transparency, and consistent updates from the developer community. Its versatility, reliability, ease of use, and extensive platform compatibility make it one of the most dependable and trusted executable compression tools available today.

Reliable, efficient, and enduring tool

In summary, UPX is a powerful and reliable executable compressor trusted by developers worldwide for its consistency and performance. Its combination of efficiency, portability, and open-source flexibility makes it a valuable tool for managing software distribution and storage. Whether for optimizing applications, reducing deployment sizes, or conserving system resources, it remains an enduring and dependable solution for modern executable compression needs.

  • Pros

    • Open-source software
    • High compression ratio with fast decompression
    • Cross-platform and supports multiple file formats
    • Maintains program performance and integrity
  • Cons

    • Limited GUI options
    • Some antivirus tools may flag compressed files
    • Command-line interface can deter beginners
    • Advanced usage requires technical knowledge
 0/1

App specs

  • License

    Free

  • Version

    4.2.4
  • Latest update

  • Platform

    Windows

    Other platforms (1)
  • OS

    Windows 95

  • Language

    English

  • Downloads

    110K

    Last month's downloads

    • 3K
  • Size

    611.54 KB

  • Developer

Also available in other platforms

Program available in other languages


Icon of program: UPX

UPX for PC

  • Free
  • 4.4
    172
  • 110K
  • V4.2.4

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Laws concerning the use of this software vary from country to country. We do not encourage or condone the use of this program if it is in violation of these laws.
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Score result: Clean

This file passed a comprehensive security scan using VirusTotal technology. It is safe to download.

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Scan Info

Last scan
Wednesday, August 13, 2025
Scan provider
VirusTotal · Full report

File Integrity

File
upx_v4.2.4.zip
SHA256
2e90ebda45b29217126d8e8ee4d0863bd9705a13adcca3ce07b7d19df55ca355
SHA1
499716711a3552f07a5d0c8c2607886ccdab2784

Softonic security commitment

UPX has been thoroughly scanned by our advanced security systems and verified by industry-leading partners. This file comes from the official developer and has passed all our security checks, showing no signs of viruses, malware, or spyware.