Debug .NET Framework, .NET Core and Unity game assemblies, no source code required
Edit assemblies in C# or Visual Basic or IL, and edit all metadata
Light and dark themes
Extensible, write your own extension
High DPI support (per-monitor DPI aware)
And much more, see below
dnSpy uses the ILSpy decompiler engine and the Roslyn (C# / Visual Basic) compiler and many other open source libraries, see below for more info.
Debugger
Debug .NET Framework, .NET Core and Unity game assemblies, no source code required
Set breakpoints and step into any assembly
Locals, watch, autos windows
Variables windows supports saving variables (eg. decrypted byte arrays) to disk or view them in the hex editor (memory window)
Object IDs
Multiple processes can be debugged at the same time
Break on module load
Tracepoints and conditional breakpoints
Export/import breakpoints and tracepoints
Call stack, threads, modules, processes windows
Break on thrown exceptions (1st chance)
Variables windows support evaluating C# / Visual Basic expressions
Dynamic modules can be debugged (but not dynamic methods due to CLR limitations)
Output window logs various debugging events, and it shows timestamps by default 🙂
Assemblies that decrypt themselves at runtime can be debugged, dnSpy will use the in-memory image. You can also force dnSpy to always use in-memory images instead of disk files.
Public API, you can write an extension or use the C# Interactive window to control the debugger
Assembly Editor
All metadata can be edited
Edit methods and classes in C# or Visual Basic with IntelliSense, no source code required
Add new methods, classes or members in C# or Visual Basic
IL editor for low level IL method body editing
Low level metadata tables can be edited. This uses the hex editor internally.
Hex Editor
Click on an address in the decompiled code to go to its IL code in the hex editor
Reverse of above, press F12 in an IL body in the hex editor to go to the decompiled code or other high level representation of the bits. It’s great to find out which statement a patch modified.
Highlights .NET metadata structures and PE structures
Tooltips shows more info about the selected .NET metadata / PE field
Go to position, file, RVA
Go to .NET metadata token, method body, #Blob / #Strings / #US heap offset or #GUID heap index
Follow references (Ctrl+F12)
Other
BAML decompiler
Blue, light and dark themes (and a dark high contrast theme)
Bookmarks
C# Interactive window can be used to script dnSpy
Search assemblies for classes, methods, strings etc
Analyze class and method usage, find callers etc
Multiple tabs and tab groups
References are highlighted, use Tab / Shift+Tab to move to next reference
Go to entry point and module initializer commands
Go to metadata token or metadata row commands
Code tooltips (C# and Visual Basic)
Export to project
List of other open source libraries used by dnSpy
ILSpy decompiler engine (C# and Visual Basic decompilers)
Roslyn (C# and Visual Basic compilers)
dnlib (.NET metadata reader/writer which can also read obfuscated assemblies)
VS MEF (Faster MEF equals faster startup)
ClrMD (Access to lower level debugging info not provided by the CorDebug API)