What is this?
It's the open-source, cross-platform .NET assembly browser and decompiler: point it at a compiled .NET assembly and it shows you the C# code behind it, on Windows, Linux, and macOS alike.
It's the open-source, cross-platform .NET assembly browser and decompiler: point it at a compiled .NET assembly and it shows you the C# code behind it, on Windows, Linux, and macOS alike.Is it a desktop app or a command-line tool?Primarily a desktop app built on Avalonia, but the same decompiler engine also ships as a dotnet CLI tool (ilspycmd), PowerShell cmdlets, and a VS Code extension.
Primarily a desktop app built on Avalonia, but the same decompiler engine also ships as a dotnet CLI tool (ilspycmd), PowerShell cmdlets, and a VS Code extension.How do I get it running?Grab the latest release from GitHub Releases or install from the Microsoft Store (RTM versions only). For the command line there's a dotnet tool (ILSpyCmd) for Linux, Mac, and Windows.
Grab the latest release from GitHub Releases or install from the Microsoft Store (RTM versions only). For the command line there's a dotnet tool (ILSpyCmd) for Linux, Mac, and Windows.Does everything work the same on Linux and macOS?Almost. The Avalonia UI and CLI are fully cross-platform, but opening assemblies from a running process or the GAC is Windows-only.
Almost. The Avalonia UI and CLI are fully cross-platform, but opening assemblies from a running process or the GAC is Windows-only.Does it phone home with the assemblies I open?No. ILSpy collects no personally identifiable information, doesn't send your files to third-party services, and uses no APM/telemetry service at all.
No. ILSpy collects no personally identifiable information, doesn't send your files to third-party services, and uses no APM/telemetry service at all.What can it do with an assembly once it's loaded?It decompiles to C# — single assemblies or whole projects — with search across types, methods and properties, hyperlink navigation, bookmarks, an assembly metadata explorer, BAML-to-XAML decompilation, and ReadyToRun .NET Core binary support. It's also extensible via plugins.
It decompiles to C# — single assemblies or whole projects — with search across types, methods and properties, hyperlink navigation, bookmarks, an assembly metadata explorer, BAML-to-XAML decompilation, and ReadyToRun .NET Core binary support. It's also extensible via plugins.Can I get decompilation inside Visual Studio or VS Code?Yes. Visual Studio 2022/2026 ship with F12 decompilation powered by ILSpy engines (v8.2 and v9.1) enabled by default, and there's a separate VS Code extension on the marketplace.
Yes. Visual Studio 2022/2026 ship with F12 decompilation powered by ILSpy engines (v8.2 and v9.1) enabled by default, and there's a separate VS Code extension on the marketplace.Can I embed the decompiler engine in my own .NET code?Yes — the ICSharpCode.Decompiler and ILSpyX NuGet packages expose the engine for use in your own projects.
Yes — the ICSharpCode.Decompiler and ILSpyX NuGet packages expose the engine for use in your own projects.What are similar projects?imewlconverter, Cpp2IL, AssetStudio, BenchmarkDotNet, uno, SteamTools, VioletToolBox, KillerPDF
imewlconverter, Cpp2IL, AssetStudio, BenchmarkDotNet, uno, SteamTools, VioletToolBox, KillerPDFWhich topics is it in?dotnetcore, unity, decompiler, c-sharp, dotnet, c#, csharp, reverse-engineering, cli-tool, gui, free, desktop-app
dotnetcore, unity, decompiler, c-sharp, dotnet, c#, csharp, reverse-engineering, cli-tool, gui, free, desktop-app