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.
Recover Data After Mac Downgrade
- Recover files lost due to macOS update, downgrade, crash, etc.
- Recover lost, deleted, formatted data
- 5 recovery modes: Basic, Advanced, Formatted Drive, Trash, Extenal Devices
- Recover files from internal and external hard drive (USB, SD Card, Media Player)
- Support file recovery on 200+ formats: video, audio, photo, docs, etc.
- Preview files before recovery
The most likely one might just be download Catalina from the app store and just do install Catalina on Big Sur's partition. If it doesn't from within Big Sur, you could make an USB installer, and try to install Catalina on Big Sur's partition from system recovery (yes, you do not need to format the drive to install over a partition that has data). But, be careful while updating the OS, as an improper installation can result in data loss. So, learn how to upgrade to macOS Big Sur without losing any data. In case of any unforeseen data loss, use a professional Mac data recovery software to recover your lost data. Download the free-to-try software from here. The key to reinstall mac OS Big Sur, Catalina or Mojave without losing data is the backup, since no one can guarantee all data will be perfectly maintained after macOS reinstallation. However, if we unfortunately lost files after macOS reinstallation, Time Machine or Cisdem Data Recovery is helpful to recover them back.
Why We Need to Downgrade Big Sur to Catalina?
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:
- New design
- Intuitively customized Safari browser
- Updated Messages app (better control of conversation)
- Redesigned Maps for better and easier navigation
- Improved transparency for Mac App Store downloads
- Expanded photo editing features
- Faster updates to the latest version
……
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:
- The Beta version is not perfect, you want to download the official version later;
- It takes longer time to get used to the new version and you don’t want to waste time;
- MacOS 11 Big Sur keeps causing problems;
- Your hardware is not highly compatible on this new version (compromised audio, video or image quality);
- Your favorite app doesn’t work on the new version;
……
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.
How to Downgrade 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.
Step 1. Prepare your Mac for downgrade
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.
Step 2. Backup files (Important and Required)
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.
- Connect an external hard drive for backup to your mac;
- Run Time Machine and set it up for backup;
- Click on the Time Machine icon in menu bar, choose Back up Now;
- Wait for the backup to finish.
Step 3. Erase macOS 11 Big Sur from your Mac
- Click Apple icon and go to Restart;
- Hold down Command+R when rebooting to reboot your mac in Recovery Mode;
- In the pop-up interface, choose Disk Utility>Continue;
- Then select your Startup Disk, click on Erase tab;
- Choose APFS or macOS Extended format and confirm to Erase.
Step 4. Install macOS Catalina or Mojave
There are 3 methods to install older macOS version on your mac.
Method 1. Download from Mac App Store and Install
- Launch Mac App Store;
- Search macOS Catalina or Mojave, click Download;
- When the download finishes, follow the on-screen instructions to install macOS Catalina or Mojave;
Method 2. Reinstall macOS Catalina or Mojave from Internet
- Click on Apple logo>Restart;
- Hold down Command+R when rebooting your mac;
- In the pop-op macOS Utilities interface, choose Reinstall macOS>Continue;
- Agree to the terms and follow the instructions to download and install.
Method 3. Reinstall macOS Catalina or Mojave from Bootable Drive
- Create a bootable drive of macOS Catalina or Mojave
- Connect the bootable drive to your mac;
- Click on Apple logo>Restart;
- Hold down Option when rebooting your mac;
- Choose the bootable drive with macOS Catalina or Mojave installer;
- Click on Continue, agree to the terms and install a previous macOS version onto your mac.
Step 5. Restore Backup with Time Machine
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.
- Click on Apple Logo>Restart;
- Hold down Command+R during mac rebooting;
- Choose Restore from Time Machine Backup from the macOS Utilities interface and click on Continue button.
- Choose the Time Machine backup disk>Continue;
- Select the latest backup, click Restore>Continue.
Step 6. Check if everything is back now!
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.
What If Data Lost/Deleted after macOS Big Sur Downgrade?
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.
Main Features of Cisdem Data Recovery
- Recover lost, deleted, formatted data;
- 5 recovery modes enable users to recover files lost under different situation;
- Recover files from internal and external hard drive (USB, SD Card, Media Player)
- Support file recovery on 200+ formats: video, audio, photo, docs, etc.;
- Support various file systems: APFS, NTFS, HFS, FAT, etc.;
- Preview files before recovery;
- High recovery rate;
How to Recover Data After macOS Downgrade from Big Sur to Catalina?
- Download and install Cisdem Data Recovery to your Mac;
Free Download - Choose a data recovery mode basing on your need. Basic mode runs a quick scan, while Advanced mode runs a deep scan;
- Select the location where you lost the files and click Scan;
- Preview the found files; All the founded files will be categorized in different folders, check the file and preview before recovery;
- Select the found file and recover them onto your mac. Check the box before found files, stop the scanning process if you want to recover before the end of a scanning process. Click Recover to get all lost files after macOS Big Sur downgrade back to your mac.
Conclusion
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.
Macs are generally known for being very dependable machines that produce little bugs, have a secure sandboxed space to fight off any intrusions (especially so since macOS 10.15 Catalina), and usually present minimum problems for the whole duration of their ownership.
However, occasionally, Macs do allow clashing processes to result in bugs, accumulate too much cache files from resource-intensive apps, and even let in a rare piece of malware if you’ve given it your admin access credentials (please don’t do it).
So there might be a time when you think that your Mac is not the same as it used to be and you probably want to queue a Mac reinstall OS process to start anew. To do that, you need to launch the Mac Recovery Mode.
What’s Mac Recovery Mode?
Chances are you might’ve never even used your Recovery Mode Mac feature before. So what is it?
Recovery Mode is an essential part of macOS utilities and lets you get out of precarious situations when your Mac is seriously stuck or some process is invading your system so much that regular Mac restarting doesn’t seem to help. A thing to do then is to boot Mac in Recovery Mode, which only allows for a few core features to operate.
In such system restore Mac environment, you’re able to:
Restore from Time Machine backup
Reinstall macOS
Get help online (browse Apple’s documentation)
Disk Utility (repair or erase your hard drive)
The natural thing to try and do if you see that your Mac is not working as expected is to go ahead and reinstall OS X. But before you proceed with the Mac system restore process, let’s see if you can fix your Mac using more accessible tools.
How to optimize your Mac the easy way
You can think about the Mac reinstall OS procedure as some heavy artillery you have at your disposal but that’s reserved for true emergencies. For most situations — Mac slowing down, files piling up, and apps spreading leftovers — a good Mac optimization software should be more than enough.
CleanMyMac X is just the kind of a powerful app that’s able to keep your Mac clean, fast, and secure in no time. It presents you with an easy-to-use toolkit and gives you access to complex operations at the click of a button. For example, you can delete all the duplicate Mail attachments, empty all the Trash bins at once, shred sensitive documents without leaving a trace, run maintenance scripts, flush DNS cache, repair disk permissions, and so much more.
Using CleanMyMac X is as intuitive as it can be:
To speed up your Mac, head to the Maintenance tab under Speed
Select Free Up RAM, Run Maintenance Scripts, Speed Up Mail, Reindex Spotlight, and anything else you find interesting
Click Run
How to boot Mac in Recovery Mode
In some rare circumstances, your Mac might become seriously unresponsive, in which case you need to know how to reinstall Mac OS X to pretty much return all system processes back to their default settings.
Another important time to do a Mac reinstall OS is when you’re planning to sell your Mac and want to wipe out all your data completely or perhaps you’ve bought a Mac with someone else’s stuff on it.
In both situations, the process for going into the Recovery Mode Mac feature is the same:
Turn off your Mac and start it back up while holding ⌘ + R
The Recovery Mode Mac menu will open. You can then choose the appropriate course of action. If you experience some systemic problems, you can just choose to reinstall macOS. If you have a Time Machine backup available, choose that. If you’re about to sell your Mac, use Disk Utility to erase your hard drive first and then start your Mac with ⌘ + R again and reinstall OS X. Click here to know more about how to use time machine on mac.
Click Continue and follow the directions for the chosen option
How to install another version of macOS
When it comes to using the system restore Mac functionality, most of the time you’d just reinstall macOS you’ve had before. A lesser known trick is to use Mac Recovery Mode to install an older (or in fact the newer) version of the operating system.
So while you use ⌘ + R to go into Recovery Mode for the same macOS, you can use Option + ⌘ + R instead to install the latest compatible macOS or Shift + Option + ⌘ + R for the possibility to get the original macOS that your Mac was shipped with or the oldest available version after that.
Why would you ever need to run an old operating system? Mostly because you might find that some software you depend on is not yet compatible with the latest version of macOS.
How to connect to WiFi in Recovery Mode
Before you go into the Mac system restore environment, it’s good to check that your WiFi is stable and fast or, better yet, connect to a wired connection via Ethernet.
Still, if your WiFi has broken down for one reason or another while you’re in Mac Recovery Mode, there’s a way out:
Find and click the WiFi icon in the menu bar
Select a WiFi network
Enter the password if needed and press Return
How to properly backup your Mac
Talking about your Mac malfunctioning and all the important macOS utilities that help you with its recovery, it’s impossible to skip the notion of conducting frequent backups — the only thing that stands between your sanity and losing all of your files in an accident. But backups are boring and not something most people would want to bother themselves with, so automation is key.
Get Backup Pro is the most flexible solution for keeping your files safe, regardless of what happens with your Mac. It offers you easy ways to synchronize your Mac with another device, to clone your hard drive to an external one, to establish a scheduled versioned backup routine, and even to do frequent incremental backups of the most important files. Even better, you can mix and match, and create multiple clones of the same files or break up your hard drive in different ways for extra security. A very small price to pay to be able to reinstall Mac OS without losing data at any time.
How to recover any Mac files quickly
You might not think about it right now, but it’s likely that at some points you’re going to lose some of your files. Maybe it’s because you’ve overwritten changes on the same document, you’ve accidentally deleted an important file, or your Mac just simply crashed. A robust backup solution would be your first go-to, but what do you do if you need the last version of the document that hasn’t yet been saved anywhere?
Disk Drill is an essential Mac recovery app that can quickly scan your affected hard drive and extract all the recently deleted information in seconds:
Open Disk Drill and wait for it to display all the connected drives
Click Recover next to the hard drive with deleted files and follow the guide
Note: Even though Disk Drill is able to recover old files in most circumstances, it shouldn’t replace your comprehensive backup strategy. Think of Disk Drill as an uber-important tool of last resort.
Here you go, now you know how to reinstall Mac OS X, speed up your Mac with CleanMyMac X, do proper backups with Get Backup Pro, and even recover lost files with Disk Drill.
Best of all, you can try CleanMyMac X, Get Backup Pro, and Disk Drill absolutely free for seven days via Setapp, a platform with more than 170 cool macOS utilities and apps that make your days 10x more productive and fun. Download them all at no cost today and see for yourself!