The ability to securely delete files is built into the OS on Macs. To securely delete a file, first add the file to the Trash Bin. Instead of just emptying the trash, choose Finder > Secure Empty Trash (see screenshot below). When you do this, not only is the file removed from the Mac’s directory, but the hard drive space it occupied is overwritten with random binary digits.

You may also adjust your settings so that files are removed securely each time you empty the trash.

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