How to Reset macOS Big Sur to Factory Settings (Full Guide)

AvatarByEric Dawson Computers & Software

Resetting macOS Big Sur to factory settings means signing out of Apple services, erasing the startup disk with Disk Utility, and reinstalling macOS Big Sur through Recovery Mode. Big Sur predates the one-click Erase All Content and Settings tool that Apple later added in macOS Monterey, so every step happens by hand: back up your files, sign out of iCloud and iMessage, boot into Recovery Mode, erase the disk, then reinstall the operating system. Intel Macs and Apple Silicon Macs enter Recovery Mode differently, and the disk erasure step also varies by model. The full process below covers both paths from backup to the final setup screen.

What You Need to Do Before You Reset macOS Big Sur

Before you reset macOS Big Sur, back up every file you want to keep, sign out of Apple’s services, and unpair any Bluetooth accessories, since none of that happens automatically on this version of macOS. A factory reset erases the whole startup disk, so anything left in place does not survive the process. Time Machine, an external drive, or a cloud service such as iCloud Drive both work for the backup itself.

  • Back up your data. Copy files to an external drive, a Time Machine backup, or cloud storage before erasing anything.
  • Sign out of iCloud. Open System Preferences, select Apple ID, then choose Sign Out, and turn off Find My Mac first to avoid an activation lock on the reset machine.
  • Sign out of iMessage. Big Sur does not sign you out automatically, so open Messages, go to Preferences, then iMessage, and sign out there separately.
  • Unpair Bluetooth devices. Remove paired keyboards, mice, and headphones from System Preferences before you erase the disk.
  • Check your internet connection. Recovery Mode needs a stable network, ideally a WPA or WEP secured Wi-Fi connection, because macOS downloads fresh during reinstallation.
  • Update M1 Macs first. Apple Silicon machines need Big Sur 11.0.1 or later installed before the reset and should stay connected to power throughout.

Keep in mind that erasing a disk through Disk Utility is not the same as physically destroying it. Data removed this way can sometimes be recovered with dedicated data recovery software, so a factory reset alone is not a strong enough guarantee of privacy before selling or donating a Mac that held sensitive information.

If I were resetting a Big Sur Mac, I would not begin Recovery Mode until I had checked the backup and signed out of both iCloud and iMessage. The erase step is simple enough once it starts, but it permanently removes files, apps, and preferences, while a missed sign-out can create an activation problem afterward. I would also unpair Bluetooth accessories before handing the Mac to someone else, since that is an easy privacy step to overlook.

How Do You Enter Recovery Mode on a Big Sur Mac

You enter Recovery Mode by holding Command and R during startup on an Intel Mac, or by holding the power button on an Apple Silicon Mac until startup options appear. Recovery Mode is where Disk Utility, the reinstall tool, and other repair utilities all live, so this is the gateway to the rest of the reset.

Intel Macs

Restart the computer and immediately hold Command (⌘) and R together. Keep holding until the Apple logo or a spinning globe appears on screen, then release once the Recovery Mode menu opens. Enter your administrator password if macOS asks for it.

Apple Silicon Macs (M1 and M2)

Turn the computer off completely, then press and hold the power button until Loading Startup Options appears on screen. Release the button, select Options, then click Continue. Enter your administrator password when prompted, the same as on an Intel Mac.

Mac Type Key Combination Additional Steps
Intel Mac Hold Command (⌘) + R on restart Hold until the Apple logo appears, then choose an option from the Recovery Mode menu
Apple Silicon (M1/M2) Hold the power button on startup Release when Loading Startup Options appears, select Options, click Continue, enter the admin password
Apple Silicon on Big Sur Hold the power button on startup Same steps as above; the Mac should be on Big Sur 11.0.1 or later for a reliable reset

Should You Reset NVRAM Before Erasing a Big Sur Mac

Resetting NVRAM is optional on Intel Macs and is not required to factory reset macOS Big Sur, but it clears out stored settings such as speaker volume, screen resolution, and the selected startup disk. NVRAM, short for non-volatile random access memory, also holds recent kernel panic details and time zone information.

  1. Step 1: Shut down the Mac completely.
  2. Step 2: Press the power button, then immediately hold Option, Command, P, and R together.
  3. Step 3: Keep holding the keys for about 20 seconds, until the Mac restarts a second time or the startup sound plays twice.
  4. Step 4: Release the keys and let the Mac finish starting up normally.

Apple Silicon Macs skip this step entirely. Settings that used to live in NVRAM are now handled inside the M1 or M2 chip itself, so a normal restart takes care of it. NVRAM resets are non-destructive either way: they clear peripheral settings without touching any files on the disk.

How Do You Erase the Disk in Disk Utility

You erase the disk by opening Disk Utility from the Recovery Mode menu, selecting the startup drive, usually named Macintosh HD, and clicking Erase, though which volumes need erasing depends on the Mac. Format the disk as APFS for any Mac running Big Sur, or Mac OS Extended (Journaled) only if you are working with much older hardware.

Mac Configuration Volumes to Erase Format Notes
Intel Mac with a T2 chip Macintosh HD only APFS The T2 chip handles the paired data volume automatically
Intel Mac without a T2 chip Macintosh HD and Macintosh HD – Data APFS Both volumes must be erased separately
M1 or M2 Mac on Big Sur Entire volume group APFS Erase the volume group, not a single volume, to avoid authorization failures

Intel Macs with a T2 Chip

Select Macintosh HD in the Disk Utility sidebar, click Erase, confirm APFS as the format, and click Erase again. The T2 chip manages the associated data volume for you, so a single erase covers the whole drive.

Intel Macs Without a T2 Chip

Older Intel Macs without a T2 chip need both Macintosh HD and Macintosh HD – Data erased separately in Disk Utility before you move on to reinstalling. Skipping the second volume can leave old files behind even after the main drive looks empty.

Apple Silicon Macs

M1 and M2 Macs store the system as a volume group rather than a single disk, so select the group itself, not just Macintosh HD, and erase it as one unit. Erasing only the inner volume can cause an authorization failure later in the reinstall.

How Do You Reinstall macOS Big Sur After Erasing the Disk

You reinstall macOS Big Sur by choosing Reinstall macOS Big Sur from the Recovery Mode menu, selecting Macintosh HD as the destination, and letting the installer finish without interruption. This step downloads and installs a fresh copy of the operating system onto the disk you just erased.

  1. Step 1: From the Recovery Mode utilities menu, choose Reinstall macOS Big Sur.
  2. Step 2: Agree to the software license terms when prompted.
  3. Step 3: Select Macintosh HD as the installation destination.
  4. Step 4: Enter your Apple ID credentials if the installer asks for them.
  5. Step 5: Leave the Mac plugged in and awake; do not close the lid or let it sleep until the install finishes.
  6. Step 6: Wait for the automatic restart and complete the setup prompts that follow.

Once setup finishes, the Mac behaves like it did on the day it left the factory, with Setup Assistant asking the usual questions about region, Wi-Fi, and Apple ID sign-in.

How Is Resetting Big Sur Different from Resetting macOS Monterey or Later

Big Sur lacks Erase Assistant and Erase All Content and Settings, the automated tools Apple introduced starting with macOS Monterey, so Big Sur users complete every step of the reset by hand. Erase Assistant on newer macOS versions signs out of every Apple service automatically before wiping the disk; on Big Sur, you sign out of iCloud and iMessage yourself first.

Erase All Content and Settings goes a step further on qualifying machines, wiping the disk and restoring the previous macOS version without a manual reinstall step. That feature needs macOS Monterey or later, along with either Apple Silicon or a T2 Security Chip, so it is simply unavailable to a Mac running Big Sur regardless of hardware. The manual Recovery Mode method described here is the only path for Big Sur.

What Should You Do if the Big Sur Reset Does Not Work

If the reset stalls or Recovery Mode will not load Big Sur, work through a short list of common causes before starting over from scratch. Most failures trace back to an outdated Mac, a weak connection, or a disk that was not fully prepared.

  • Try First Aid first. If the Mac is only acting slow rather than failing to erase, running First Aid in Disk Utility can resolve some issues without wiping anything.
  • Update M1 and M2 Macs. Confirm the machine was updated to Big Sur 11.0.1 or later before the reset; an older build is a common reason reinstallation refuses to proceed.
  • Check the network. A dropped or weak Wi-Fi signal during the reinstall step can interrupt the download; move closer to the router or use a wired connection if one is available.
  • Consider cloning instead of erasing. When you are not fully ready to lose the current setup, disk cloning to external media preserves everything while you decide, rather than forcing an immediate erase.
  • Restore selectively if a full reset is not possible. On a Mac that cannot complete the standard process, back up and restore only the files and settings you need rather than attempting a full erase.

How Long Does a Full Big Sur Reset Take

None of the sources consulted for this guide give an exact time for a complete Big Sur factory reset, though they agree the reinstall portion depends heavily on your internet connection speed. Downloading a fresh copy of macOS Big Sur during Recovery Mode takes noticeably longer on a slow or congested connection than on a fast one.

Plan the reset for a window when you do not need the Mac right away, and stay on reliable Wi-Fi or a wired connection for the whole process. A Mac left plugged into power and undisturbed tends to move through Recovery Mode, erasure, and reinstallation with fewer interruptions than one that gets closed or unplugged partway through.

Older Intel Macs on slower broadband generally take longer than recent Apple Silicon models on a fast fiber connection, simply because the installer has to download in full rather than resume from a cached copy. Budget an afternoon rather than a quick coffee break, and treat any estimate you see elsewhere online as a rough guess rather than a guarantee, since none of the sources behind this guide publish a fixed number.

Frequently Asked Questions

Do I Need to Reset NVRAM on an M1 Mac?

No. Apple Silicon Macs, including M1 and M2 models, do not need an NVRAM reset. The settings that used to live in NVRAM are now handled by the chip itself, so a normal restart is enough.

Can I Recover Files After I Erase the Disk in Disk Utility?

Sometimes. Erasing a disk in Disk Utility removes the file system references but does not always destroy the underlying data right away, so dedicated recovery software can occasionally pull files back. Treat a backup as the only reliable safeguard, not the erase step itself.

What Happens if I Forget to Sign Out of iCloud Before Resetting?

Forgetting to sign out and disable Find My Mac before erasing can leave an activation lock on the Mac afterward. You will likely need to enter the original Apple ID credentials again to get past setup on the freshly reset machine.

Should I Format the Disk as APFS or Mac OS Extended (Journaled)?

Choose APFS for any Mac running Big Sur, since it is the format Apple designed for modern solid state drives and current macOS versions. Mac OS Extended (Journaled) exists mainly for older systems and is not the recommended choice here.

Is There a Faster Way to Reset a Big Sur Mac than Recovery Mode?

Not on Big Sur. The one-click Erase All Content and Settings tool only works on macOS Monterey or later with Apple Silicon or a T2 chip, so Recovery Mode with manual sign-out, erase, and reinstall steps remains the only option on this version.

How Do You Know the Factory Reset Worked?

Setup Assistant is the clearest sign. That screen, asking for a region, a Wi-Fi network, and an Apple ID, only appears on a Mac that just finished a fresh macOS installation, so reaching it means the erase and reinstall both completed. Checking that your old files, apps, and accounts are gone confirms the same thing from the other direction.

A Big Sur factory reset takes patience rather than complicated tools: back up first, sign out of Apple’s services by hand, pick the right Recovery Mode path for your Mac, erase the correct volumes, and reinstall before handing the Mac off or starting fresh yourself. Following the sequence in order avoids the activation locks and authorization failures that trip up rushed attempts.

What This Page Does Not Publish

  • I do not estimate how long the reset takes, because download and installation time varies with your connection.
  • I do not cover recovery failures or FileVault preparation in this guide.
  • I do not offer a separate test for confirming a successful reset beyond completing the setup process.

References

Author Profile

Eric Dawson
Eric Dawson
I'm Eric Dawson, the writer behind The Money Watch. I live in the Columbus, Ohio area and I write about the ordinary questions that turn out to be complicated: computers, shopping, food, travel, parking, small businesses, fees, rules and products. Every article starts with the official page, the maker or the agency, then the sources that check it, and I say plainly where they disagree and what I would do. More about how I work is on the About page.