How to Downgrade macOS Big Sur to Catalina 2021

Have you updated to macOS Big Sur recently? Do you no longer want to use macOS Big Sur on your Mac? Maybe you installed it to try out new Big Sur features as well as changes. But you’re not happy about it because of the Big Sur incompatibility, performance issues, or a problem you could not solve. In that case, you can expect to downgrade to an older version of macOS, such as macOS Catalina. However, this is not difficult as long as you regularly back up Time Machines on your computer. 

Users of macOS Big Sur or any other macOS software update will regret updating their device and need to go back to the older version installed. The easiest way to downgrade macOS Big Sur is to format your Mac and restore it with a Time Machine backup made before installing macOS Big Sur.

If you are looking to turn your Mac software into an older version, this article will help you step by step how to properly downgrade your Mac from macOS Big Sur to MacOS Catalina. 

How to Downgrade macOS Big Sur to Catalina 2021

Warning: Before you proceed, make sure you already have a Time Machine backup before installing macOS Big Sur. If you do not have a backup, you will not be able to downgrade it. Doing this will cause your drive to be formatted or deleted, resulting in permanent data loss.

Additionally, suppose you have important data or files created after updating to macOS Big Sur. In that case, you will need to manually transfer them to an external drive, as Time Machine will not restore this data. If you do not have a backup, do not proceed. 

• First of all, connect the Time Machine drive to your Mac. This driver must contain a backup of your Mac made before installing the macOS Big Sur, and you will restore your data from this drive.
• Then, restart your Mac by clicking on the Apple logo from the menu bar and select Restart from the menu.
• After booting your Mac, immediately hold down the Command + R keys to boot into your Mac Recovery Mode.
• The macOS Utility screen opens and selects Disk Utility to start.

• In the left pane, select the disk drive where macOS Big Sur is installed and click on Erase.

• You can see format options for the drive and enter the desired name for the drive and select the file system format as “Apple File System (APFS)” (if you are using a Mac with an SSD) or “Mac OS Extended Journal (HFS+)” (for Macs with mechanical and hybrid hard disks). Then, click Erase to confirm and format your Mac. Clicking that will erase all data on the drive. So please do not do it unless you are sure you have a backup. 

• Once you format the drive successfully, you will see a message and click on Done to exit the Disk Utility.

• Next, click Restore from Time Machine from the macOS utility, and click on Continue.

• Now, your Mac will start searching for available backups. Select the Time Machine drive connected to your Mac as the restore source and click Continue.

• Select the latest backup of the macOS version you need to downgrade and select the destination drive name to restore the macOS Time Machine backup in the Select a backup screen.

• This should be the only drive we have fully formatted. Now, click Restore to start restoring the Time Machine backup to the selected drive.

Now, you have to wait patiently until the whole process is over. Depending on the speed of hard disk and the backup’s size, the restoration and downgrade process may take some time. 

After the reboot is complete, the Mac will automatically restart and start directly on the macOS version activated when the selected Time Machine backup was created. For example, if a Time Machine backup was created during the macOS Catalina installation, your macOS Catalina will reboot after the restoration.

In this article, we focused on downgrading from the macOS Big Sur to macOS Catalina. You can use these specific steps to downgrade to any version of macOS. The only requirement is to have a Time Machine backup of your data with the macOS version you hope to downgrade.

We hope you will be able to downgrade from macOS Big Sur to macOS Catalina successfully. What are the reasons, and why do you downgrade? Do you know other ways to downgrade Mac? Let us know your ideas and share your experiences in the comment section below.