Secure File Deletion in Mac OS X

For Apple computers that either have a SSD for hard drive, or are running Mac OS X 10.11:

Secure Delete is ineffective on computers that use Solid State Drives (SSDs), and the Secure Delete option has been removed from Mac OS X 10.11 (El Capitan) as Apple moves to SSDs in all of their new computers.
 
For these computers, we recommend you encrypt the computer with File Vault.  
When deleting a file on a computer where File Vault is enabled, the deleted file data will remain encrypted.
 

 

If you are using a Mac that is running OS X 10.4 through 10.10 and it has a spinning hard drive (typically all desktop Macs and most laptops that have a CD/DVD drive), you can either also use File Vault, or continue to follow the directions below to use Secure Delete when emptying the trash.

To check if your computer has a SSD or spinning hard drive:

  1. Click on the Apple logo in the menubar and select About this Mac.
  2. Click either System Report or System Info
  3. In the System Information report, go to Hardware > Storage.
  4. If there are two panes on the right, in the top right pane, click on the drive that is your main hard drive (typically Macintosh HD).
  5. In the bottom right pane, look for the Physical Volume section.
  6. Look for the Medium Type field.
    • It will either say Rotational (spinning hard drive), or SSD.
    • If it is Rotational, you can use the Secure Empty Trash below, or encrypt via File Vault.
    • If it is SSD, you can only secure your files via File Vault.

To Secure Empty Trash on a spinning hard drive:

  1. Drag the files or folders you wish to securely delete to the Trash, located at the far right end of the Dock.
  2. Click once on the Trash icon to open the Trash folder and make sure you are ok with permanently deleting all files and folders in the Trash.
  3. From the menubar, choose Finder > Secure Empty Trash.
  4. You will see a warning message alerting you that the files will be deleted.  Click OK to start the secure deletion process.
    • NOTE: The Secure Emprty Trash process takes slightly longer than a normal emptying of the Trash because the files and folders are overwritten several times to make them unrecoverable.
  5. Once the progress bar disappears, all files and folders that were in the Trash have been securely erased and are completely irrecoverable.