Telerik Justdecompile Offline Installer Link
It is widely considered one of the fastest decompilers on the market, rivaling tools like ILSpy and dotPeek.
Most .NET libraries (Newtonsoft.Json, Entity Framework, etc.) have permissive licenses allowing decompilation for debugging. However, commercial obfuscated software is off-limits. Telerik’s own UI libraries are obfuscated; JustDecompile will show you IL but not clean C#. telerik justdecompile offline installer link