How to shred files with BleachBit

A file shredder erases a file so that it cannot be recovered. Instead of just crossing it off the index (see how deleting works), it writes new random data over the place where the file was stored.

Which tool?

BleachBit is a free, open-source program. It has two features that matter here:

• Shred files or folders. Erases the ones you pick.
• Wipe free space. Overwrites the empty space on a drive, so that old deleted files in it are gone too.

An important warning first

Shredding works well on traditional spinning hard drives. It is not reliable on solid-state drives (SSDs), USB sticks and SD cards. These drives move data around internally, so overwriting a file may leave the original copy behind. Most modern laptops and phones use SSDs. If that is you, read "SSDs and Macs" below.

Install BleachBit on Windows

1. On the BleachBit website, open Download and choose BleachBit for Windows.
2. Run the installer and follow the steps.
3. Open BleachBit from the Start menu.

Shred a file or folder

1. Open BleachBit.
2. Open the menu at the top (it may look like three lines or say File).
3. Choose Shred files (to shred single files) or Shred folders.
4. Pick what you want to erase and confirm. This cannot be undone.
5. Wait until it says it has finished.

Wipe free space

1. Open BleachBit and open the File menu.
2. Choose Wipe free space.
3. Pick the drive and confirm. This can take a long time on big drives.

On Linux

• Install BleachBit from the package that matches your system, or from your software centre.
• Use the same menu steps as above.
• To shred one file from the Terminal, type: shred -u filename. The -u also deletes the file after shredding.

SSDs and Macs: the safer approach

When shredding is unreliable, encryption is the answer:

1. Turn on full-disk encryption from the start (BitLocker on some Windows versions, FileVault on Mac, LUKS on Linux).
2. To get rid of everything, destroy the key by erasing the drive. On a modern Mac, use Erase All Content and Settings. Without the key, the data is unreadable.
3. For a drive you are throwing away that was never encrypted, overwrite the whole drive. A free tool for that is Darik's Boot and Nuke (DBAN), which works on spinning disks.

What shredding does not erase

• Copies in backups, in the cloud and in emails.
• Traces in "Recent files" lists, history and thumbnails. Use BleachBit's cleaning options for some of these.
• Anything stored on another drive that you forgot about.

Habits that help

• Encrypt first, shred second.
• Keep sensitive files in an encrypted Cryptomator vault.
• When in doubt, assume deleted does not mean gone.