Does overwriting a file actually make it unrecoverable?

On a traditional spinning hard drive, overwriting the file's sectors with random data makes recovery impractical. On an SSD, wear-levelling and over-provisioning mean an overwrite may not touch the original physical cells, so full-disk encryption plus a secure erase or crypto-erase is the reliable approach.

Why is srm missing on modern macOS?

Apple removed the srm command from recent macOS versions because secure-erase of individual files is unreliable on SSDs and APFS. The recommended path is FileVault full-disk encryption, after which a normal delete plus a Trash empty is effectively unrecoverable without the key.

What does cipher /w do on Windows?

cipher /w does not delete a specific file. It overwrites the free space on a volume, so the contents of files you have already deleted normally can no longer be recovered. Delete the file first, then run cipher /w on its drive.

Is any file or path sent anywhere?

No. You type a path purely so the tool can drop it into the right command template. No file contents are read, and nothing is uploaded or transmitted. The tool is just a command builder.

How many overwrite passes do I need?

For modern drives a single pass of random data is considered sufficient by NIST guidance; the old 35-pass Gutmann method targets obsolete encoding schemes. The shred command defaults to three passes, which is more than enough for a spinning disk.

Secure File Deletion Guidance Tool

Dragging a file to the Trash does not erase it — the bytes usually sit on disk until something else overwrites them, and forensic tools can recover them. Secure deletion overwrites the data (or, on SSDs, relies on encryption and crypto-erase) so it cannot be recovered. The catch is that the right command differs by operating system and by drive type, and the syntax is easy to get wrong. This tool builds the correct command for your situation from a path you type — nothing is uploaded, it is purely a command generator.

How it works

Secure deletion has two regimes:

Spinning hard drives (HDD) store data in fixed physical sectors. Overwriting the file’s sectors with random data reliably destroys the contents. Tools: shred and wipe on Linux, and historically srm on macOS.
Solid-state drives (SSD) use wear-levelling: the controller spreads writes across cells and keeps spare capacity, so an overwrite command may land on different cells than the original data. Per-file overwriting is therefore unreliable on SSDs. The dependable approach is full-disk encryption (FileVault, LUKS, BitLocker) plus a normal delete, or a whole-device secure/crypto-erase.

The tool maps your OS and drive type to the appropriate command:

Linux  HDD : shred -vfz -n 3 "<path>"      (3 passes, then zero, then remove)
Linux  SSD : rm -P "<path>" ; fstrim -v /   (delete then TRIM; rely on FDE)
macOS  HDD : rm -P "<path>"                 (overwrite-on-delete, older HW)
macOS  SSD : rm "<path>"  + FileVault note  (per-file overwrite unreliable)
Windows    : del "<path>" ; cipher /w:<drv> (delete then wipe free space)

Notes and warnings

Secure deletion is irreversible — double-check the path before running. On SSDs, the honest answer is that the single most effective control is having had full-disk encryption enabled the whole time; once the key is destroyed the data is gone regardless of cell state. For an entire SSD, the manufacturer’s ATA Secure Erase (or a crypto-erase) is better than any file-level command. This tool never reads or transmits your files; it only assembles the command text for you to run yourself.