upx/upx

Health v2 · maintenance only

Flags: no_license

Adoption not part of the score

17816 stars · 1520 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

UPX is a free, open-source executable packer that compresses programs and DLLs by roughly 50-70% while keeping them fully self-contained and runnable. It supports many executable formats across Windows, macOS, and Linux and is written in portable C++.

Use cases

• compress executables to reduce download size
• shrink binaries for software distribution
• pack a DLL to save disk space
• unpack a UPX-compressed binary
• reduce network load times for program downloads

When to choose

• you need to reduce the size of distributed binaries without changing their behavior
• you want a reversible, well-documented packer with no runtime or memory penalty
• you need cross-platform support for Windows, macOS, and Linux executables

When to avoid

• you need actual code protection or encryption - UPX explicitly provides none
• your target format is unsupported (e.g., ARM64 Windows is still pending)
• your antivirus pipeline flags packed binaries and you cannot whitelist them

Facets

cli-tool · maturity stable

compression cli developer-tools developer-tools cross-platform windows cli cross-platform executable-packer binary-compression self-extracting c-plus-plus command-line linux macos

Member repositories

For agents

markdown · JSON · MCP: product_card(name="upx/upx")