How do I clear my entire hard drive on a Mac?

Clearing the entire hard drive on a Mac can be a useful step when selling or giving away your computer. It erases all of your personal data, restores the Mac to factory settings, and removes any installed programs. This leaves the Mac ready for the new owner to use. Here is a step-by-step guide on how to fully clear a Mac’s hard drive.

Table of Contents

Back Up Your Data

Before wiping your hard drive, it’s essential to back up any files you want to keep. This includes documents, photos, music, movies, app data, settings, and more. An external hard drive or cloud storage makes backing up your data simple. Here are some backup options:

Time Machine – Apple’s built-in backup software works seamlessly with an external hard drive. Plug in the drive and turn on Time Machine to get automatic, continuous backups.

iCloud – For Macs running macOS Catalina or newer, you can use iCloud to back up files, photos, emails, contacts, calendars, and more.
Cloud storage – Services like Dropbox, Google Drive, OneDrive, and Box offer generous free storage tiers to back up files.
Clone your hard drive – Use cloning software like Carbon Copy Cloner or SuperDuper to make an exact copy of your hard drive on an external drive.

Once you’ve completed your Mac backup, it’s safe to proceed with erasing the hard drive.

Restart in Recovery Mode

To wipe the hard drive, you’ll need to start up in Recovery Mode:

Shut down your Mac.

Restart your computer and immediately press and hold Command + R on your keyboard.
Keep holding the keys until you see the Recovery screen appear.

This loads recovery tools from a separate partition to allow erasing the main hard drive.

Run Disk Utility

The Recovery screen has an option to launch Disk Utility. This is the tool we’ll use to erase the hard drive.

Click on Disk Utility in the Recovery menu.
Click Continue if any message pops up.

Disk Utility will open with a list of drives on the left.

Select your main hard drive volume from the list. Its name is typically “Macintosh HD.” Then click the Erase button in the toolbar.

Choose an Erase Format

You’ll see a pop-up with options for erasing the hard drive:

Name – Type a name for the new volume.
Format – Choose APFS for modern Macs or Mac OS Extended (Journaled) for older Macs.
Scheme – GUID Partition Map is standard for most Mac setups.

The key setting is Format – stick with APFS or Mac OS Extended for full compatibility. Once your settings are chosen, click Erase to wipe the drive.

Confirm the Erase

Disk Utility will show a confirmation popup before wiping the hard drive. Click Erase to confirm again. This securely erases all data by overwriting the entire drive.

For an older traditional hard drive, this may take over an hour.

For a newer SSD drive, the erasing process takes just a few minutes.

You’ll see a progress bar that indicates when the disk erase is complete. Don’t interrupt the process until it finishes.

Quit Disk Utility

Once done, you can quit Disk Utility:

Click the Disk Utility menu and select Quit Disk Utility.
This will take you back to the Recovery screen.

Now your hard drive is fully erased and ready for macOS reinstallation.

Reinstall macOS

With the disk erased, you can proceed to reinstall macOS:

In the Recovery menu, select Reinstall macOS.
Follow the onscreen steps to install a fresh copy of the Mac operating system.

This will install the latest macOS version your Mac is compatible with.

The reinstallation will automatically reformat the hard drive and partition it correctly. Once done, your Mac will boot up to a fresh new setup.

Alternative: Use Terminal to Erase Drive

You can also erase your Mac’s hard drive from the command line using Terminal:

Launch Terminal from the Recovery menu.
Type diskutil list and find your hard drive identifier.
Use diskutil eraseDisk JHFS+ "Macintosh HD" disk#, replacing “disk#” with your disk id.

Add -verbose to get status updates as it erases.

This allows choosing JHFS+ instead of APFS format if needed for older Macs. The erase process will now run in Terminal.

Alternative: Use Third-Party Tools

Some other disk utility tools can erase your Mac’s hard drive outside of the Recovery options:

Drive Genius – Bootable tool for erasing drives via high security options.
Disk Drill – Option to wipe free disk space to make previously deleted files unrecoverable.
Erase It – Specifically designed for erasing and reformatting hard drives.

These give you added flexibility like securely wiping free space. But Recovery Mode is simpler for fully erasing and reformatting the entire drive.

Before Selling Your Mac

Once your Mac’s hard drive is fully erased using these steps, it’s ready to be sold or given away. Here are a few other tips before handing off your device:

Unregister iMessage – This releases your phone number from iMessage activation.

Sign out of iCloud – Prevent the new owner from accessing your iCloud data.
Remove Apple ID from App Store – Have the new owner use their own Apple ID.
Remove device enrollment – Check there are no Mobile Device Management (MDM) profiles.

Doing this ensures a fully clean handover. The Mac will be restored to like-new condition for the next owner.

Before Recycling Your Mac

If you plan to recycle your old Mac instead of selling it, you still need to erase your personal information using these steps. However, there are a few extra precautions to take:

Remove SIM card – Take out any SIM card from a cellular-enabled MacBook.

Disable Find My Mac – This will allow the Mac to be reactivated.
Log out of all accounts – Ensure no accounts remain logged in.
Erase external devices – Wipe any external storage drives separately.

You want to protect your privacy but also ensure the Mac can be reused or recycled properly. Taking these extra steps will allow for safe recycling of your old computer.

Conclusion

Clearing out a Mac completely requires booting into Recovery Mode and using Disk Utility to fully erase the hard drive. Make sure to back up your data first. Then you can choose to reinstall macOS for a like-new setup, or recycle the wiped Mac. With an external drive and the Recovery partition, you now have the process to quickly and securely erase everything on a Mac.