Deleted isn’t gone.
Overwritten is.

No — it only removes the directory entry that points to them. The actual data stays on the drive until it happens to be overwritten by something else. Free recovery tools can restore “deleted” files in minutes. Overwrite replaces the data itself with zeros or random passes, which is why it’s unrecoverable.

Yes. For modern flash media, a single pass is generally sufficient because of wear-leveling algorithms — and Overwrite tells you exactly that in the app rather than pushing you to burn write cycles. Multi-pass standards (DoE, DoD, Gutmann) are there when policy or peace of mind requires them.

Deliberately, no. For your safety, the internal boot drive is protected and hidden — Overwrite is designed exclusively for external and secondary drives: USB sticks, SD cards, external SSDs and HDDs. You can’t accidentally nuke your Mac.

Never. Overwrite executes fully offline with absolute zero telemetry — no analytics, no tracking, no external servers. Even the erasure certificates are generated and signed locally on your Mac using ECDSA keys.

A PDF report generated after a wipe that records the device, method, pass count, and result — cryptographically signed on-device. It’s proof of sanitization for buyers, employers, or auditors, aligned with the NIST 800-88 standard for media sanitization.

Overwrite detects read-only APFS partitions and hidden volume snapshots before wiping and guides you through resolving them, so you never end up with a wipe that silently didn’t stick.

Use both tools for the job. Macs from 2018 onward (T2 chip or Apple silicon) encrypt their internal drive in hardware — even with FileVault off — so Apple’s built-in “Erase All Content and Settings” destroys the encryption keys and permanently sanitizes the Mac itself. Then run Overwrite on every external drive, USB stick, and SD card that goes with it — those have no built-in protection at all. (Older Intel Macs: turn on FileVault, let it finish, then erase.)