How do I wipe and factory reset my Mac?

by
How do I wipe and factory reset my Mac

Resetting your Mac to its original factory settings is an important step if you plan on selling or giving away your computer. A factory reset erases all of your personal data, accounts, settings, and apps from the Mac, leaving it in the same condition as when you first took it out of the box.

Here are some common questions about resetting a Mac:

Why should I reset my Mac to factory settings?

There are a few key reasons to wipe your Mac and restore it to factory default settings:

  • Erase all personal data before selling or giving away your Mac
  • Resolve persistent software issues or performance problems
  • Eliminate viruses, malware, or other security threats
  • Clear out clutter and start fresh with a clean Mac

Resetting removes all your files, settings, apps and accounts from the Mac, leaving it in a clean “out of the box” state. This is important for protecting your privacy if you plan on selling or gifting the Mac.

What data is erased when resetting a Mac?

Resetting your Mac erases all of the following from the computer:

  • User accounts and related settings
  • Apps you’ve downloaded and installed
  • Files and folders in your user account
  • System settings and preferences
  • Cached and temporary files
  • Web browsing history and cookies
  • Keychains containing account names and passwords

Essentially, the Mac is returned to the blank state it was in when you first took it out of the packaging.

How do I back up my Mac before a reset?

Before erasing your Mac, it’s crucial to back up any important files you want to keep. Here are some backup options:

  • Use Time Machine to back up files to an external hard drive
  • Manually copy important files to an external drive
  • Use cloud storage like iCloud or Dropbox to backup files online
  • Ensure photos are synced to a cloud service like iCloud Photos

After backing up your files, double check the external drives or cloud services to ensure the data is there. It’s wise to have more than one backup before resetting your Mac.

How do I factory reset a Mac with Apple Silicon or Intel processors?

The steps to factory reset a Mac differ slightly depending on whether it has an Apple silicon chip (M1 or M2 models) or an Intel processor:

Reset Apple Silicon Mac (M1/M2 models)

  1. Power on your Mac and log in
  2. Go to System Preferences > Erase All Content and Settings
  3. Follow the onscreen instructions to erase your Mac
  4. When the reset completes, follow the Setup Assistant prompts to reinstall macOS

Reset Intel-based Mac

  1. Power on your Mac and log in
  2. Go to System Preferences > Startup Disk
  3. Select your current startup disk, click “Erase”, then confirm the erase
  4. Your Mac will reboot into Recovery mode to reinstall macOS
  5. Follow the onscreen prompts to reinstall macOS and setup the Mac

The steps are very straightforward on both Apple Silicon and Intel Macs. Simply access the erase function in System Preferences, confirm the reset, and let the Mac reformat itself.

How do I reset a Mac without losing macOS?

If you wish to reset your Mac to factory settings but keep your current macOS version installed, follow these steps:

  1. Back up your files as normal
  2. Restart your Mac into Recovery mode by holding Command-R while powering on
  3. Select Disk Utility from the Recovery menu
  4. Choose your startup disk and click “Erase” to reformat it
  5. Quit Disk Utility when finished erasing
  6. Go to the Recovery menu and choose to Reinstall macOS
  7. Follow the prompts to reinstall macOS on the freshly erased startup disk

This process erases your disk but saves you the time of downloading the full macOS installer again. It reuses the existing OS files already on your startup disk.

How can I erase a Mac remotely?

If you need to erase a Mac remotely, such as an employee’s device when they leave a company, use these methods:

  • Use remote management software to send a wipe command
  • Enable Find My Mac, sign in to iCloud.com, and remotely erase the device
  • Set a firmware lock to prevent the Mac from being used until it is erased

Consult your IT department on the best way to remotely wipe company-owned Macs when needed. This protects sensitive company data after an employee departure.

Is there a quick way to reset my Mac without reinstalling macOS?

If you simply need to erase your personal data and settings but wish to skip reinstalling macOS, try these shortcuts:

  • Press Command-Option-P-R on boot to reset NVRAM/PRAM
  • Boot to Recovery mode and run Disk Utility’s Erase function
  • Use the csrutil command in Terminal to disable System Integrity Protection
  • Reboot in Safe Mode to clear out certain system files and caches

These shortcuts can reset specific parts of the Mac system without a full reinstallation. However, a clean install is still recommended for the most thorough wipe.

Should I reset both macOS and recovery partitions when erasing my Mac?

When resetting your Mac using Disk Utility, you’ll see options to erase both the macOS partition and the Recovery HD partition. Here are the differences:

  • macOS Partition – Contains the main operating system files and your data. Erasing it removes all apps, accounts, and personal files.
  • Recovery HD – Contains utilities for reinstalling macOS and troubleshooting issues. You can erase it, but your Mac will then require internet recovery.

For a thorough factory reset, it’s best to erase both partitions. Just keep in mind your Mac won’t have local restore options until you redownload the macOS installer.

How can I securely erase free space on my Mac’s drive?

To add an extra level of security when selling or gifting your Mac, you can use Disk Utility to perform a secure erase of the free space on your startup drive. This overwrites deleted files to prevent recovery.

  1. Boot to Recovery mode by holding Command-R on startup
  2. Select Disk Utility from the utilities menu
  3. Choose your startup drive and click the Erase button
  4. Select “Mac OS Extended (Journaled)” for the format
  5. Enable “Secure Erase” and pick a 3-pass or 7-pass wipe
  6. Click Erase to securely wipe unused space

This sanitize free space without harming your macOS install. Combined with a standard erase of the partitions, it provides peace of mind your data is erased.

Should I reset SMC and NVRAM when resetting my Mac?

Resetting your Mac’s NVRAM and SMC can help clear out system-level settings and caches. Here’s when to reset them:

  • NVRAM – Resetting NVRAM clears out settings tied to your hardware. Do this when erasing your Mac.
  • SMC – The SMC controls power and hardware functions. Reset it if having issues after an erase.

Resetting NVRAM is useful when factory resetting Macs. The SMC only needs reset if you experience low battery life, thermal issues, or other hardware problems after erasing the Mac.

How can I securely erase an older Mac running OS X or macOS?

On older Macs running OS X/macOS 10.7 or earlier, the steps to securely erase your Mac are a bit different:

  1. Restart your Mac and hold Command-S to boot to single user mode
  2. Type /sbin/mount -uw / and press Enter to mount the drive as writeable
  3. Run rm -rf / to start deleting all files securely
  4. Once complete, type reboot to restart your Mac
  5. Upon reboot, reinstall macOS from the recovery partition or external installer

For maximum security, you can also wipe free space by using diskutil secureErase freespace 3 in Terminal before step 5.

If I factory reset my Mac, will it remove the MDM profile from my organization?

If your organization has applied an MDM (mobile device management) profile to your work-issued Mac, a standard factory reset will not remove the MDM policy restrictions. You would need your administrator to release the Mac from their MDM server.

Some options to consider:

  • Ask your IT department to remove the Mac from MDM before wiping it
  • Perform a secure erase of the entire disk to remove all data including MDM
  • Do a fresh reinstall of macOS after erasing the startup disk

To fully clear MDM profiles from a managed Mac, the device must be released on the organization’s MDM server before a reset.

Conclusion

Resetting your Mac clears out all your personal data and provides a clean slate. Be sure to backup your files, erase both partitions, reinstall macOS, and reset NVRAM. This will return the Mac to factory-fresh condition.

Doing a full factory reset gives you peace of mind when selling, gifting or recycling your Mac. Take your time and use the step-by-step instructions outlined in this article to securely wipe your Mac.