5 Things to Do Before and After Reformatting Your Mac

The innards of a hard drive.

Wiping your Mac’s hard drive is a different task than even a few years ago. If you use macOS Big Sur, you have the Recovery tool. As such, reformatting your Mac is more straightforward than the recent past.

In this post, we give you a checklist of things to do before reformatting your Mac. Before that, let’s give you a rundown of the macOS Recovery tool.

A Primer on the macOS Recovery Tool

Apple now makes the process of reformatting your Mac a snap. In years gone by, there would be a standoff between your backup hard drive, the Mac auto installer, and even physical recovery disks. What’s more, you would need to be in the right boot mode to carry out the process.

Now though, we have macOS Recovery. In a nutshell, this Disk Utility is wrapped up with a few other tools. It has a nice interface and is a breeze to use compared to previous versions.

While there’s much to cover using macOS Recovery, lots of it is beyond the scope of this article. Still, we encourage you to check out Apple’s official documentation, as it’s laid out well and informative.

5 Things to Do Before and After Reformatting Your Mac

On the whole, a clean install of your Mac includes backing up your current system, removing instances of your Apple ID from the system, wiping the hard drive using macOS Recovery, and reinstalling it through Time Machine.

As such, there are a few things you can do before and after. Let’s get into it!

1. Back Up Your Entire System

The first task is to back up your system. The most integrated approach is to use Time Machine.

The Time Machine app.

It should be noted that some users have issues with Apple’s native solution. As such, there are a number of other solutions at your disposal. Though, for the majority of users, Time Machine “just works”.

You may already have automatic backups enabled, so this should already be sorted. Though, it’s a good idea to run one last backup to catch every file and folder.

To do this, make sure you select “Show Time Machine in menu bar” within the “System Preferences -> Time Machine” panel. Then, click “Back Up Now” within your Time Machine icon in your toolbar:

Backing up a Mac through Time Machine.

You may have to wait a while, but once the backup is complete, you can move on to more administrative tasks.

2. Grab the Installers for Your Most Recently Used Apps

A great thing about backing up using Time Machine is that your system will be preserved, including all of your apps and settings. Though, it’s still a good idea to collect all of the installers for your most used apps, as there will be hiccups within the restore process that you won’t foresee, and won’t be because of macOS Recovery.

Our advice is to use Screen Time to check out which apps you use the most over a week.

The Screen Time app.

From there, collect your installers and back them up, too. You may not need them, but you’ll be glad to have them.

3. Collect All Licenses and Serial Numbers for Your Apps

One other aspect you may miss is to have passwords, licenses, and serial numbers handy. It could be that these don’t port over during the restore process, but again, you’ll be glad you have them.

There are many great apps that will help you store keys, but the bad news is that you have to put in the work. However, Bitwarden, 1Password, and more all let you store important information.

The Bitwarden website.

Once you have these in place, stored within your password manager, you can continue to work on the deauthorization process.

4. Deauthorize Any Apps that Use Your Apple ID

Apple gives you much advice to “factory reset” your machine; that also applies to reformatting your Mac.

In a nutshell, you want to sign out and deauthorize your computer from apps such as Apple Music, iMessage, iCloud, etc. In fact, any app that uses a restricted number of licenses should be on your list here.

While Apple Music may not need your input, if you use iTunes, you will have to do this. Also, signing out of iCloud is a good idea, too, and you can cause issues between your devices if you don’t deauthorize iMessage.

For third-party apps, checking your purchase history may help you deauthorize some apps, although much like your serial numbers, you may have to dig into your emails or accounts to find out more.

5. Restore macOS, Your Files, Folders, and Settings

Once you have everything ready, we recommend you make one more backup (again to catch any changes). In other words, whatever you do, make backing up the very last action before reformatting your Mac.

To start the reformat:

1. Start up your computer in macOS Recovery:

  • On a Mac with Apple silicon: Choose “Apple menu -> Shut Down,” press and hold the power button until you see “Loading startup options,” select Options, click Continue, then follow the on-screen instructions.
  • On an Intel-based Mac: Choose “Apple menu -> Restart,” then immediately press and hold Command + R.
Shutting down a Mac.

2. In the Recovery app window, select Disk Utility, then click Continue.

3. In Disk Utility, select the volume you want to erase in the sidebar, then click Erase in the toolbar.

4. Type a name for the volume in the Name field, click the Format pop-up menu and choose APFS, then click “Erase Volume Group.”

5. When the erase process is complete, click Done, then choose “Disk Utility -> Quit Disk Utility.”

6. In the Recovery app window, select “Reinstall macOS Big Sur,” click Continue, then follow the onscreen instructions.

Our final piece of advice has to do with general crashes or freezes. This is an under-documented issue that can cause you some pain. For example, I had to reinstall Big Sur on an Intel MacBook Pro and transfer data through Time Machine to it.

The process took a few attempts, and there were a few freezes along the way. It is best to use a wired connection to the Internet where possible, and give the process time, especially if you’re transferring from an old physical disk drive such as a Time Capsule.

For any hard freezes, you will need to shut off the Mac by holding the power button. From there, boot up again as normal and continue the process.


Apple’s approach to reformatting your Mac on modern systems is such a breeze that you may want to carry out a format every week! Of course, if you don’t plan on this, the good news is that by using macOS Recovery, you can be done and dusted within no time.

If you’re unsure about the Mac’s different startup modes, we’ve covered it in the past. Do you have any tips for reformatting your Mac that we haven’t covered? Let us know in the comments section below!

Tom Rankin
Tom Rankin

Tom Rankin is a quality content writer for WordPress, tech, and small businesses. When he's not putting fingers to keyboard, he can be found taking photographs, writing music, playing computer games, and talking in the third-person.

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