Mike Cobb, director of engineering at the data-recovery firm DriveSavers, noted that your flash drive’s vendor may provide an app with simpler secure-erase tools, pointing to ones from Intel, SanDisk and Samsung. On a Mac, open the Disk Utility app, select the drive, click “Erase,” then click “Security Options…” and move the slider control to the third, “3-pass secure erase” option. On a PC, open the command prompt from the Start Menu and type “format e: /p:3,” (if “e” isn’t the letter for the flash drive, change that accordingly). You can still use the method of dumping random data three times in a row on an entire flash drive, although tools to do that are less than obvious in both Windows 10 and macOS High Sierra.

It didn’t want people thinking they could scrub a file from a drive when the attempt might not succeed on a flash drive.

That’s why Apple removed the “Secure Empty Trash” command from the macOS Finder in 2015’s El Capitan version. If you’re not sure if your external drive is flash or not, seeing if it fits cleanly into a shirt pocket should is your easiest cue, followed by its complete absence of noise.īut when it’s time to wipe a drive so you can sell or donate it to somebody else, flash drives impose complications that hard drives don’t: Because they automatically move bits of data to less-used areas of the drive to extend longevity, the traditional secure-erase technique of overwriting files with random data may not clear out all of it. Flash drives work faster and, since they store data in solid-state memory instead of on spinning magnetic platters, they also work longer.Īnd they’re a lot smaller. The computer industry’s migration from hard drives to flash drives has mostly brought good things. When it's time to donate or ditch an old flash-memory drive that stored sensitive information, deleting those files isn't enough. The safest way to wipe the slate clean is actually to encrypt it - and that's not as hard as it sounds.

How to clear a usb stick