Corrupt a DLL File Online
Corrupt a Windows .dll file online for free. Destroys the PE header and export table so no application can load the library.
- No upload
- No size limit
- No sign-up
Corrupt your DLL file
Tuned for .dll, .ocx, .sys, and works with every other format too.
Why DLL files are hard to corrupt properly
A DLL is a PE binary like an EXE, but it fails differently and more interestingly. Applications load libraries at runtime, so a corrupted DLL does not stop a program starting. It makes it fail at the moment it reaches for a function, which is exactly the class of error that is hardest to diagnose in production.
What this tool destroys
- The PE header. The MZ stub,
PE\0\0signature and optional header are destroyed, so the loader rejects the image. - The export table. The directory listing every exported function name and ordinal is overwritten.
- The import table. The libraries this DLL itself depends on can no longer be resolved.
- Section data. Entropy is scattered through the code and resource sections.
What you will see afterwards
| Application | Behaviour |
|---|---|
| Application startup | "The application was unable to start correctly (0xc000007b)." |
LoadLibrary | Returns NULL with ERROR_BAD_EXE_FORMAT. |
| regsvr32 | "The module failed to load" when registering. |
| Dependency tools | Report an invalid or unreadable PE image. |
Common reasons people do this
- Testing that an application reports a missing or invalid dependency clearly.
- Verifying a plugin host isolates a bad library instead of crashing entirely.
- Reproducing the classic "0xc000007b" support scenario for a runbook.
- Checking that an updater validates library files after download.
How to corrupt a DLL file
- Drop your .dll file onto the box above, or click to browse.
- Leave the level on Standard unless you want partial damage (Light) or need to defeat recovery software (Heavy).
- Press Corrupt file. Processing happens on your device, so it finishes almost immediately.
- Download the result. It keeps the original filename and byte length by default.
DLL FAQ
Why corrupt a DLL rather than an EXE?
Because the failure mode is different and much harder to diagnose. The application starts normally and fails later, at the moment it tries to use the library, which is exactly the scenario support teams need to practise.
Will it break the whole system?
Only for applications that load that specific library. Never corrupt system DLLs in a Windows directory, work on copies.
Does it work on .sys drivers?
Yes. Kernel drivers are PE binaries too and use the same profile.
Is the original library modified?
No. A corrupted copy is generated in memory and downloaded separately; the file you selected is only read.