From Jun 2020 to Aug 2020, Apple has released several beta versions for macOS 11 Big Sur, both developers and testers can install and run it on a supported Mac. You may be one of them, starting to use this new macOS but unfortunately run into some issues and want to revert to previous Catalina or Mojave version.
No worries, here we will list the easy steps to downgrade macOS Big Sur to Catalina without losing data.
Upgrading from macOS Catalina 10.15 or Mojave 10.14? Go to Software Update in System Preferences to find macOS Big Sur. Click Upgrade Now and follow the onscreen instructions. Upgrading from an older version of macOS? If you’re running any release from macOS 10.13 to 10.9, you can upgrade to macOS Big Sur from the App Store. Feb 03, 2020 Downgrade from Catalina to Mojave on Some New Macs. Apple has started installing Catalina on new Macs other than the 16-inch MacBook Pro and 2019 Mac Pro, but since these older Macs can still run Mojave, it’s possible—if a bit tricky—to downgrade them to Mojave. One of my production Mac is still on Mojave. I want to update to Catalina and not Big Sur (waiting for dust to settle down). Automatic update from system preferences only proposes Big Sur as well as some patch updates for MacOS 10.14.6.
MacOS 11 Big Sur is absolutely the biggest update these years since it has moved from 10 to 11, you can find a bunch of update as following in Big Sur:
All the revealed new updates added to macOS11 Big Sur stimulate mac users to upgrade and take the first bite on this macOS version. But later, there occurs problems and some of them want to revert to the previous Catalina version for one or another reasons:
No matter what your reason is to revert to an older version, you can refer to following part to downgrade from Big Sur to Catalina without losing data.
To downgrade Big Sur to Catalina without losing data, here are 6 steps to follow. Before the downgrade, your data matters the most, so don’t forget to back them up though it takes time to finish a backup.
You should quit running programs and leave enough space (15GB to 20GB) to install Catalina after erasing Big Sur from your Mac hard drive. Also, make sure your mac is connected to the internet for later macOS installer download.
It is safe to upgrade or downgrade a macOS version, there is no harm done to your files or data, but data loss after mac update or reversion happens sometimes. If you don’t want to render your data under any potential risks, you are highly recommended to back up files.
There are 2 ways to back up file, either back up your files to an external hard drive with Time Machine or upload your data to cloud-based service for storing, like iCloud, DropBox, OneDrive. But here Time Machine backup is recommended.
There are 3 methods to install older macOS version on your mac.
The only change you want for the downgrade is turning back to a previous macOS version, but you want the files and settings the same as before. In this case, you should restore both your files and settings from a Time Machine backup.
Now, run your apps on macOS Catalina and check if everything goes well.
If the downgrade still causes problems, restart your mac or reinstall Catalina/Mojave to fix it.
But what if we still got data lost or deleted after macOS Big Sur downgrade to Catalina or Mojave? You can recover them back with Time Machine backup by following the tutorial in above Step 5. If this still cannot get back your files, you need a professional data recovery program---Cisdem Data Recovery.
Cisdem Data Recovery is a program to recover lost, missing, deleted, formatted files from both internal and external hard drive on mac. It applies to data loss due to system crash, update or downgrade, also supports file systems like APFS, HFS+, FAT16, FAT32, exFAT, NTFS, etc.
No matter you want to downgrade from Big Sur to Catalina or Mojave without losing data, or just want to upgrade from an earlier version to the latest macOS, the backup process is mandatory in case of any data loss. If a data loss happens and you don’t have a backup, you will need a dedicated program like Cisdem Data Recovery to do the job.