How to securely erase an external SSD drive

You are forgiven for thinking that using Disk Utility’s Erase function is secure enough to return or give away your external SSD disk.

However, all it does is just format the disk in the quickest way, sort off like a “wipe out the old data.”. Though, any recovery tool will still be able to get to your data.

If you do not, have an SSD disk, then Disk Utility provides Security Options when you use Erase. But what about an SSD drive?

Why you cannot securely erase an SSD disk is outlined in this great Tidbits post that goes into more details.

Though, you are here to learn how to erase your disk nonetheless. If you start searching online, you will see that software vendors quickly point to their apps (which costs quickly $69 or more). However, with the command line, you can do it yourself.

Fire up your favorite terminal (Warp is currently my favorite) and type:

diskutil list

This will give you the list of your drives. Look for the attached drive. As you can see from the screenshot, mine was “disk4”. Once you have identified the drive (double check the drive ID), you can use the following command to erase the SSD disk securely:

diskutil secureErase 1 disk4

Again, make sure you use the exact drive.

(There are other algorithms that you can use too. Check them with the command “man diskutils”)

Once you hit enter, you should see the progress bar. Be prepared for a long wait and a scorching drive!

If you want to mount the drive on your Mac again, you must use Disk Utility to format the drive.

I hope this helps.