Mac: Disk Utility Secure Erase

Created on: May 13, 2014
Last updated: August 22, 2017

If you need to securely erase a hard drive or SSD, you can use the OS X / macOS Disk Utility to perform this task.

  1. Open the Disk Utility.
  2. Using the Sidebar, select the volume you wish to erase.
  3. Click the Erase tab.
  4. Choose a drive format – for general usage "Mac OS Extended (Journaled)" is typically the best option. If you're using 10.13 or later, APFS is also a viable option.
  5. Give the drive a new name.
  6. Click the "Security Options..." button. 
  7. Move the slider until the description reads ". . . a single pass of zeroes. . . ". Click OK.
  8. Click "Erase...". A dialog box will drop down inside the window. Click Erase a second time to confirm.

Depending on the size of the volume, the process can take several minutes to well over an hour. One pass of writing zeros will clear all data from the volume with little or no chance of recovery. Note there are more secure erase options that add extra passes of zeroes to conform with DOE and DOD requirements, however this can drastically increase the time required to erase the drive. Choose these options at your own discretion.