Utility

Secure File Shredder

Overwrite file contents before deletion, and understand where shredding does and does not work.

Last reviewed by the Radiatus Cloud team

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Deleting removes the pointer, not the data

A normal delete unlinks the filename and marks the space reusable. The bytes stay on disk until something overwrites them, which is why undelete tools recover files routinely. Overwriting the contents first is what makes recovery from the raw sectors impractical.

One pass is enough on modern drives

The 35-pass Gutmann method was designed for MFM and RLL encoding used by drives of the early 1990s and has no benefit on any current hardware. A single pass of zeros or random data makes magnetic recovery infeasible on a modern platter drive. Multi-pass wiping mostly wastes time and drive life.

SSDs cannot be shredded reliably

Wear levelling means the controller writes new data to different physical cells, so overwriting a file's logical blocks leaves the original cells intact and unreachable through the filesystem. Copy-on-write filesystems, snapshots, and journals cause the same problem on any medium. For an SSD the working answers are full-disk encryption with key destruction, or the drive's own secure erase command.

Copies survive elsewhere

Shredding one file leaves backups, cloud sync history, version control, temporary files, swap space, thumbnail caches and email attachments untouched. Anything genuinely sensitive has usually existed in several places, and shredding the original addresses only one of them.

Encryption from the start is the real answer

Data encrypted before it is written is unrecoverable once the key is gone, regardless of what physical remnants remain. That is a design decision rather than a cleanup step, and it is why full-disk encryption has largely replaced shredding as the standard practice.

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Frequently Asked Questions

Why is deleting a file not enough?

Because delete removes the filename pointer and marks the space reusable. The bytes remain until overwritten, which is why undelete tools work routinely.

How many overwrite passes are needed?

One is enough on modern drives. The 35-pass Gutmann method targeted encoding used in the early 1990s and has no benefit on current hardware.

Does shredding work on an SSD?

Not reliably. Wear levelling writes new data to different physical cells, leaving originals intact. Use full-disk encryption with key destruction or the drive's secure erase.

What does shredding miss?

Backups, cloud sync history, version control, temporary files, swap space and thumbnail caches. Anything sensitive usually exists in several places.

Privacy & Security

Simulation only - no actual deletion.

Data: None
Client-side-Side
Active
v1.0

About This Tool

This tool runs entirely in your browser. No data is sent to any server, ensuring complete privacy. Simply use the interface above to get started — no registration or login required.

Disclaimer: This tool is provided "as is" without warranty of any kind. Results are for educational and utility purposes.