How to Erase Startup Disk on Mac?

Complete guide to thoroughly cleaning your Mac!

If you intend to donate or sell your Mac, you should first delete the data on it. You don't want your data, including files, images, videos, and programs, to be on the Mac when you sell it.

If your Mac has some software issues and is not working as expected, and the First Aid in disck utility cannot fix the problem, you may remove data on the drive and reinstall macOS.

This article will demonstrate how to erase the startup disk (also called system drive, boot drive) on your Mac if it is experiencing problems.

Method 1: Erase Mac Startup disk in macOS Recovery mode

Before you sell or donate your Mac, you'd better reset it to factory settings. After logging out of iCloud account on your Mac, just shut down your Mac, then turn on into macOS Recovery mode to erase all data from the startup disk.

#1 erase startup disk of an Intel-based Mac

Step 1. Turn on your Mac, then immediately press and hold Command + R keys until you see an Apple logo or other image.

Step 2. If asked, select a user you know the password for, then enter their administrator password.

Step 3. From the utilities window, select Disk Utility and click Continue.

Step 4. Select the Mac startup disk (such as Macintosh HD) from the left pane. Then click on Erase button to securely erase all data from the Mac startup disk.

Step 5. When done, quit Disk Utility to return to the utilities window.

Step 6. If you want your Mac to start up again from the volume you just you erased, select Reinstall macOS in the utilities window.

#2 erase startup disk of an Apple Silicon chip Mac

Step 1. Turn on your Mac and continue to press and hold the power button until you see the startup options window. Select Options, then click Continue.

Step 2. If asked enter your Mac login password. From the utilities window, select Disk Utility and click Continue.

Step 3. Select the Mac startup disk and click on Erase button.

Step 4. Quick Disk Utility and then go to Reinstall macOS.

Note: the data which is erased by Disk Utility is not lost forever. With data recovery software, anyone still can recover lost data which is erased by Disk Utility.

Method 2: Permanently wipe Mac startup disk with Data Eraser

Donemax Data Eraser for Mac is a powerful, safe and easy-to-use data erasure software. It can help you securely and permanently erase data on a Mac and make data recover become impossible.

If you want to permanently erase data on a Mac startup disk, just try the two modes below.

Mode 1. Erase Files.

This mode will help you selectively shred files and folders from your Mac startup disk. Just open Donemax Data Eraser for Mac and then add files/folders to the erasure list. Click on Erase Now button to securely and permanently erase all selected files/folders.

Mode 2. Erase Free Space.

This mode will erase free disk space of the Mac startup disk and permanently erase all deleted/lost files. It will not erase the existing files on your Mac.

Just delete the files you want to erase on your Mac, then empty trash bin.

Open Donemax Data Eraser for Mac, select data erasure mode - Erase Free Space. Select the Mac startup disk and click on Erase Now button. All deleted/lost files on the Mac startup disk will be erased permanently.

Please note than once the data is erased by Donemax Data Eraser for Mac, the data is lost forever, can't be recovered by any data recovery software.

With the safe data eraser, you can securely and permanently erase data from Mac disk, external hard drive, memory card, USB flash drive, digital camera, etc. It will not cause any damage to your disk and 100% safe for SSD erasure. Before you sell or give away your Mac, you can use this software to securely wipe all data from the Mac startup disk so that no body can recover your private information.