Corrupt an ISO File Online
Corrupt an ISO disc image online for free. Destroys the 32 KB system area and volume descriptors so the image cannot be mounted or burned.
- No upload
- No size limit
- No sign-up
Corrupt your ISO file
Tuned for .iso, .img, .cue, and works with every other format too.
Why ISO files are hard to corrupt properly
An ISO 9660 image begins with a 32 KB system area, followed by volume descriptors at fixed offsets and path tables that map the directory tree. Because those offsets are fixed rather than pointer-driven, tools can often recover an image with scattered damage, the structures are exactly where they are expected to be.
What this tool destroys
- The system area. The first 32 KB, which holds boot code on bootable images, is overwritten in full.
- Volume descriptors. The
CD001primary volume descriptor at offset 0x8001 and its terminator are destroyed. - UDF descriptors. The
BEA01,NSR02andNSR03markers used by UDF images are targeted too. - Path tables and payload. The directory structure is destroyed and entropy is scattered through the image body.
What you will see afterwards
| Application | Behaviour |
|---|---|
| Windows mount | "Sorry, there was a problem mounting the file." |
| macOS DiskImageMounter | "No mountable file systems." |
| Rufus / balenaEtcher | Rejects the image as invalid before writing. |
mount -o loop | "wrong fs type, bad option, bad superblock." |
Common reasons people do this
- Testing that an OS deployment tool verifies images before writing.
- Verifying a download validates its checksum rather than trusting the file.
- Simulating a bad burn or interrupted download for a support runbook.
- Checking that a virtualisation platform reports a bad ISO clearly.
How to corrupt a ISO file
- Drop your .iso 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.
ISO FAQ
Why does the header region need to be so large?
Because ISO 9660 reserves the first 32 KB as a system area and only puts the primary volume descriptor at offset 0x8001. Anything smaller would leave the descriptor untouched.
Will a bootable ISO still boot?
No. The boot code lives in the system area, which is overwritten in full.
Does it work on hybrid ISO/UDF images?
Yes. Both the ISO 9660 and UDF descriptor sets are targeted, so hybrid images break completely.
Can a large ISO be handled in the browser?
Yes. Files are processed in 8 MB slices, so a multi-gigabyte image works without exhausting memory.