Free · No signup required

Protect your .NET code in seconds

Upload a .NET DLL or EXE and download an obfuscated copy. Names are rewritten to make reverse engineering harder. Keep your original and test the protected copy before shipping.

Obfuscate a file See Pro features

Obfuscate

Your tier: Free · Max 1 MB per file · Up to 1 file per batch

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Drop your .DLL or .EXE here

or click to browse · up to 1 MB

Obfuscate public names — applications only, ignored for libraries

Block ILDasm — refuses the legacy disassembler

Pro Deeper protection options

More protection for larger projects. See Pro →

Encrypt string literals — hides URLs, keys and messages from decompilers

Obfuscate control flow — reorders method bodies into tangled goto flow

Hide API calls — routes external calls through generated proxies

Virtualize marked methods — compiles methods you tag with [Virtualize] into a private VM; opt-in per method

Tamper-proof virtualized methods — couples the virtualized methods so patching the compiled output breaks them instead of running altered; needs Virtualize

Include rename map — downloads a .zip with a private map to decode stack traces from your obfuscated build; never stored

Processed in memory. Your original file stays unchanged.

No source code required

Works on the compiled .dll or .exe directly — no project files, rebuild, or debug symbols needed.

Built for .NET assemblies

Protect compiled code with symbol renaming. Keep public library APIs intact, and test reflection and serialization in your app.

Files never stored

Uploads are processed in memory and streamed back. Nothing is written to disk or kept.

Coming soon

A native desktop app

We're building a Windows desktop version of FreeObfuscator that runs the same obfuscation engine entirely on your machine. No upload — your DLLs and EXEs never leave your computer, so it works fully offline and fits code you're not permitted to send to a server.

It isn't out yet. When it ships we'll announce it on the changelog.

Before you ship

Obfuscation is easy to apply and easy to misunderstand. These cover what it genuinely protects, what breaks and why, and whether this tool is the right one for your situation.

Concept What obfuscation actually protects against An honest breakdown of the threats it addresses — and the ones it does not. Guide What breaks, and why Reflection, serialization, XAML and DI are the usual suspects. Each with its fix. Use cases Is this right for your situation? Desktop apps, paid libraries, licensing, on-premise software and client deliverables. .NET .NET obfuscator How .NET obfuscation works, what each protection layer does, and what it can't protect. C# C# obfuscator You wrote C#; it compiles to a .NET assembly. How to protect it, and what to test. EXE EXE obfuscator Protect a .NET application executable so its logic can't be read back from the shipped .exe. DLL DLL obfuscator Shipping a library? Obfuscate the .dll so callers can use it without reading your source. Comparisons How we compare ConfuserEx, Dotfuscator, .NET Reactor and others — including where they win.