Download dnSpy – Free .NET Assembly Decompiler, Editor, and Debugger

dnSpy is a free, open-source .NET assembly editor, decompiler, and debugger that allows developers and reverse engineers to inspect, modify, and debug .NET assemblies without access to the original source code. It is one of the most powerful tools in the .NET ecosystem for analyzing compiled applications, fixing bugs in third-party libraries, and understanding the internals of .NET software.

Built on the ILSpy decompiler engine, dnSpy can decompile .NET assemblies back to readable C# or Visual Basic code with high accuracy. Its integrated debugger supports setting breakpoints, stepping through decompiled code, inspecting variables, and modifying runtime values, all without needing a project file or source code.

dnSpy also supports editing assemblies directly at the IL (Intermediate Language) level or by modifying decompiled C# code, making it invaluable for patching, modding, and reverse engineering .NET applications. It works with .NET Framework, .NET Core, .NET 5+, and Unity game assemblies.

Key Features

• Decompile .NET assemblies to readable C# and Visual Basic code with high accuracy.
• Integrated debugger with breakpoints, step execution, variable inspection, and call stack.
• Edit assemblies at the IL level or via decompiled C# code without original source.
• Supports .NET Framework, .NET Core, .NET 5/6/7/8, and Unity game assemblies.
• Search across all open assemblies for types, methods, fields, and string literals.
• Analyze references and call hierarchies to understand code structure.
• Open source, previously under MIT license (now archived), widely used in the .NET community.

How to Install

1. Download the dnSpy ZIP archive for your system (x64 or x86) from the link below.
2. Extract the archive to a folder of your choice, no installation required.
3. Run dnSpy.exe to launch the application.
4. Go to File → Open to load a .NET DLL or EXE assembly for inspection.
5. Browse the assembly tree, double-click any method to view decompiled code, and use Debug → Start Debugging to attach the debugger.