# ILSpy

.NET Decompiler with support for PDB generation, ReadyToRun, Metadata (&more) - cross-platform!

Repository: https://github.com/icsharpcode/ILSpy
Canonical: https://ross.abutalabs.com/products/ilspy
Language: C#
License: MIT
License Family: permissive
Topics: decompiler, decompiler-engine, c-sharp, dotnet, dotnetcore, mono, unity, pdb, ilspy, decompile
Last push: 2026-08-26T20:53:29+00:00

## Health v2 (maintenance only)
Score: 98/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 97, longevity 100
- inputs: {"age_days": 5689, "days_push": 7, "days_rel": 21, "gap_med": 27, "n_releases_24m": 12}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 25954, forks 3698 (observed 2026-08-28T04:11:38.761234+00:00)

## What it is
ILSpy is an open-source, cross-platform .NET assembly browser and decompiler that converts compiled .NET binaries back into readable C# source code. It ships as a desktop GUI built on Avalonia, plus a CLI dotnet tool, editor extensions, and NuGet libraries (ICSharpCode.Decompiler) for embedding decompilation.

## Use cases
- decompile a .NET dll back to C# source
- inspect the contents of a compiled .NET assembly
- recover source code when only binaries are available
- generate PDB files from .NET assemblies
- browse and analyze third-party NuGet package internals
- decompile assemblies from the command line in CI
- analyze Unity or Mono game assemblies

## When to choose
- you need to read or recover C# code from compiled .NET binaries
- you want a free, open-source alternative to .NET Reflector or dnSpy
- you need cross-platform decompilation on Windows, Linux, or macOS
- you want to embed a decompiler engine in your own tooling via NuGet

## When to avoid
- you need to decompile JVM bytecode or native binaries rather than .NET assemblies
- you require debugging or live patching of assemblies (tools like dnSpy are better suited)
- you need obfuscation removal or guaranteed perfect source recovery

## Facets
- artifact type: application
- maturity: active
- function: reverse-engineering, developer-tools, gui, cli, parser
- domain: developer-tools, reverse-engineering, programming-languages
- platform: windows, cross-platform, dotnet, cli
- tags: decompiler, dotnet, csharp, assembly-browser, pdb, avalonia, nuget-library, linux, macos

## Member repositories
- icsharpcode/ILSpy (main) score 98
- icsharpcode/AvaloniaILSpy (mirror) score 10

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:11:38.761234+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T16:55:57.373297+00:00, confidence not recorded.
  - readme: https://github.com/icsharpcode/ILSpy (fetched 2026-08-28T04:11:38.761234+00:00, sha 9c3c8554d2b2)
- Data as of 2026-08-30T08:39:29.467469+00:00.