How to Clean Install macOS Big Sur 11.0

Want to upgrade your Mac to the newest version of macOS which is Big Sur?

Recently, Apple has released its latest and greatest version of macOS, also known as Big Sur. The brand new operating system for their Mac computers packs upgraded icon design, tweaks on the menu bar, and many more. 

While the updated version of the operating system can normally be installed using software updates, it is best that you perform a clean install of the latest operating system. 

This way, files, and resources from the previous version of macOS are completely gone from your system which if left behind can cause implications like macOS Big Sur slowing down

Today, we are going to show you how to update your Mac by performing a clean install of macOS Big Sur 11.0. 

Before getting started, visit Apple’s official site to verify if your Mac is compatible with macOS Big Sur. 

Now, let us proceed to the actual steps.



Backup Your Mac. 

Since a clean install would wipe out all the contents of your hard drive, it is a good practice that you back up your files first to avoid data loss. 

Thankfully, macOS has a built-in tool for creating backups called Time Machine. Have an external drive ready to store your backup. 

  1. First, connect your external drive to your Mac using a USB or Thunderbolt cable
  2. After that, click on the Apple logo located at the top-left corner of your screen and select System Preferences

clean install macOS Big Sur


  1. Inside System Preferences, click on Time Machine


  1. Now, click on Select Backup Disk and choose your external drive as storage. 

clean install macOS Big Sur


  1. Click the Choose button afterward.
  2. Finally, Time Machine will immediately start backing up your Mac computer. 

Wait for the process to complete, which can take several minutes depending on your computer. Once the backup is done, proceed to the next step below. 



Create a Bootable Disk. 

The bootable disk is the main tool that you would need for installing macOS Big Sur on your Mac. This would contain the actual installation files of the operating system, and it is important that you create it properly. 

Now, there are a few ways on how to create a bootable drive, but we are going to show you the simplest way: which is by using built-in tools on macOS. 

Check out the steps below to guide you on the process: 

  1. First, download macOS Big Sur on your Mac
  2. After that, open Finder and go to the Applications tab from the side menu. 
  3. Now, click on Utilities and open Disk Utility


  1. Inside the Disk Utility, select your external drive and format it as ‘Mac OS Extended (Journaled)’. For Scheme, leave it at Master Boot Record.
  2. Hit the Erase button afterward. 


  1. Go back to the Utilities folder and open the Terminal which would be used to convert your external drive to a bootable device. 
  2. On the Terminal, type the following command and replace ‘Untitled’ with the name of your external drive.

sudo /Applications/Install\ macOS\ Big\ –volume /Volumes/Untitled 

clean install macOS Big Sur


  1. Finally, type Y and hit Return to proceed. A ‘Done’ message should appear on the terminal once the process is done. 

After doing this, you are now ready to install macOS Big Sur on your Mac. 



Installing macOS Big Sur. 

Before installing macOS Big Sur, make sure that you already backed up your data as there is no going back after doing this process. 

In addition, make sure that your Mac is plugged in properly or your MacBook has enough charge to complete the process to avoid any issues. 

  1. First, insert the bootable drive on your Mac. 
  2. After that, restart it while holding down the Option key on your keyboard. 
  3. The Boot Options screen should appear on your screen, select your external device, and open the Disk Utility

clean install macOS Big Sur


  1. Inside the Disk Utility, click on the drive you wish to install macOS and hit the Erase button
  2. After erasing the drive, go back to the Utility screen and select Install macOS
  3. Finally, click on Continue and follow the on-screen prompts to proceed with the installation process. 

clean install macOS Big Sur


Once Big Sur is done installing, your device should restart automatically. 



New Features on macOS Big Sur. 

Here are some new features that you should look forward to after installing macOS Big Sur on your computer. 


Updated Menu Bar. 



The menu bar on Big Sur is now taller and more transparent to have that edge to edge effect on your desktop wallpaper. Labels on the buttons are now bigger for better readability, and it adjusts its color depending on your desktop picture.


Improved Control Center. 


clean install macOS Big Sur


The updated Control Center on Big Sur gives you a favorites menu where your most-used menu bar items are displayed for faster access.

Controls for features that you use most like Battery and Accessibility are also added to the Control Center. 


Redesigned Notification Center. 


clean install macOS Big Sur


While the design of the latest version of macOS was improved, the Notification Center saw a lot of changes like interactive notifications and a transparent user interface. 

Notifications are put in a single column together with your widgets and automatically sorted by most recent. Widgets on the Notification Center like Calendar, Stocks, and Weather are also redesigned to give the operating system an overall new look. 

This wraps up our guide on how to perform a clean install with macOS Big Sur 11.0. If you have other questions and concerts, simply leave a comment below, and we would try our best to answer them. 


If this guide helped you, please share it. 🙂


  • John Sixto

    John is a staff writer at Saint and comes from a SAP ABAP development background. He has a Bachelors in IT and has been writing since 2018, with over 500 posts published. He loves to build PCs and has a deep curiosity in understanding how different components and configurations work. John spends hundreds of hours at a time, researching and testing the software and apps, before he proceeds to write about it. LinkedIn X (Twitter) Website

    View all posts
Leave a Reply

Your email address will not be published. Required fields are marked *