Corrupt a 7z Archive Online
Corrupt a 7z archive online for free. Destroys the signature header and packed stream index so 7-Zip cannot list or extract the contents.
- No upload
- No size limit
- No sign-up
Corrupt your 7z file
Tuned for .7z, and works with every other format too.
Why 7z files are hard to corrupt properly
7z keeps its metadata in a compressed header at the end of the file, with a small signature header at the start pointing to it. That indirection makes 7z particularly brittle once either end is damaged, and particularly reliable to break.
What this tool destroys
- The signature header. The
7z\xBC\xAF\x27\x1Cmarker and the offset it carries to the end header are destroyed. - The end header. The compressed metadata block listing every file, folder and coder is overwritten.
- The packed stream index. The structure mapping compressed streams to their contents is destroyed.
- Compressed payload. Entropy is scattered through the LZMA streams so nothing is recoverable by carving.
What you will see afterwards
| Application | Behaviour |
|---|---|
| 7-Zip | "Cannot open the file as archive" or an unexpected end-of-data error. |
| PeaZip / Keka | Reports an unsupported or damaged archive. |
7z l | Fails with "Headers Error" and a non-zero exit code. |
| Windows Explorer | No preview and no extraction option beyond a generic error. |
Common reasons people do this
- Testing an extraction service against malformed archives.
- Verifying a software distribution pipeline validates its packages.
- Simulating a partially downloaded archive for a retry-logic test.
- Checking that unpacking failures are reported rather than silently skipped.
How to corrupt a 7z file
- Drop your .7z 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.
7z FAQ
Why is 7z easy to break?
Because it stores its file listing in a compressed header at the end and reaches it through an offset at the start. Damage either and the archive has no map of itself.
Does 7-Zip have a repair mode?
Not a real one. Unlike RAR it has no recovery records, so a damaged 7z is generally unrecoverable, which is why this tool is so effective on it.
Are encrypted 7z archives supported?
Yes. Encryption protects the contents, but the signature and end headers we target sit outside it.
Will the archive size change?
Not by default. The output is byte-for-byte the same length as the original.