Reko
Reko is a free decompiler that turns machine-code binaries into a high-level language.
What Reko is
Reko is a free decompiler that turns machine-code binaries into a high-level language. It can be used through a graphical shell, a command-line program, or a .NET library, and accepts either individual executable files or project files with added information to guide decompilation or format output. Its supported-binaries page lists processor architectures and executable formats, with support maturity indicated for each. The Windows installer includes GUI and command-line clients for 32-bit and 64-bit x86 Windows. The guide describes running Reko on non-Windows machines using Mono, while the README lists .NET 9.0 as an installation prerequisite. A cross-platform Avalonia GUI is under development. Useful output may require users to supply type information, comments, and readable procedure names. The project is licensed under GPL-2.0 and warns that some software licenses prohibit decompilation or reverse engineering. Users can report issues or ask questions through the issue tracker or Reko chatroom; the project says volunteers build it in their spare time.
Good
- Free under the GNU General Public License, version 2.
- Offers GUI, command-line, and .NET library access.
- Accepts executables and information-bearing project files.
- Documents architectures, formats, and support maturity.
Watch out
- Useful results may require added types and comments.
- Cross-platform Avalonia GUI is still under development.
- Some software licenses prohibit decompilation or reverse engineering.
Who it suits
Reko is for developers and others who need to inspect machine-code binaries through a GUI, command line, or .NET library. It suits users willing to provide extra type and procedure information and check whether decompilation is permitted for the software involved.
Verdict
Reko offers several ways to work with binaries and supports project files that can add context. Expect to check support maturity and applicable software licenses, and to provide extra information for useful results.
Plans and prices
From Reko's own pricing page, checked 7 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Free | Free | Freely available under the GNU General Public License |
The facts
Each one read from Reko's own pages, with the date it was checked.
What it does
- Architecture and format support
- The supported-binaries page lists processor architectures and executable formats, with support maturity indicated for each.checked 7 Oct 2026
- License and use
- The repository identifies Reko as GPL-2.0 and warns that some software licenses prohibit decompilation or reverse engineering.checked 7 Oct 2026
- Other operating systems
- The user's guide describes running Reko on non-Windows machines using Mono, and the README lists .NET 9.0 as a prerequisite for installation.checked 7 Oct 2026
- Project files
- The decompiler accepts individual executable files or Reko project files, which can contain extra information to help decompilation or format output.checked 7 Oct 2026
- Purpose
- Reko decompiles machine code binaries into a high-level language.checked 7 Oct 2026
- Support
- Users can report issues or ask questions on the issue tracker or in the Reko chatroom; the project says it is built by volunteers in their spare time.checked 7 Oct 2026
- User assistance
- The guide says useful decompilation can require users to provide type information, comments, and friendly procedure names.checked 7 Oct 2026
- Ways to use it
- Reko can be used through a GUI shell, as a command-line program, or as a .NET library.checked 7 Oct 2026
Where it runs
- Cross-platform GUI
- The README says a cross-platform Avalonia GUI is under development.checked 7 Oct 2026
- Windows installation
- The user's guide says the Windows installer installs both GUI and command-line clients and supports 32-bit and 64-bit x86 Windows.checked 7 Oct 2026
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