Downgrading on Mac

#productivity #resources #macos #apple

Upgrading / Downgrading on a Mac

It is easy and recommended to upgrade your MacOS from one version to a later version. But occasionally there comes a situation where we want to downgrade. This can happen if your new operating system is heavy on the existing hardware of your system which pretty much cannot be upgraded, or if your development environment starts breaking on a later version (a thing that happened with me), or simply you don't like the user interface and aesthetics of the new version.

The truth

The truth simply put is there is no simple method for downgrading on a Mac, nor is it recommended by Apple. So, if one is stuck on an ugly looking desktop, there is not much you can do about it. You can use the built-in tool Time Machine but suppose it is not configured to create backups. Then, the only option is to create a bootable USB flash drive or use the Mac Recovery Options. I will talk here about the latter option which requires an internet access.

Mac Recovery

Built into every Macbook, apple intel or apple silicon, is a recovery option that you can access and use it to erase and format the hard drive and install an operating system. Yes, that's right! The steps described here are for apple silicon m1/m2/m3/m4 Macs: -

Before we begin, it will be important to highlight here that to downgrade your operating system, you will have to first erase your hard drive and then a fresh copy of an older version operating system can be installed on the system. That means all the data will be wiped, so be sure to create a backup of the data first if you have some important data on your computer.

Tweaking the boot security options

Shut down your Mac following the normal procedure.
Turn on the laptop by pressing and holding the power button. A message will be shown to hold the power button to load the recovery options. You can leave the button as soon as the recovery options start to load.
Click on Options. This will navigate you to a screen with your user account. Log into your account by using your password.
This will open the MacOS Recovery Utilities. Here some options will be presented like the following: -

a. Restore from Time Machine Backup

b. Reinstall MacOS

c. Safari

d. Disk Utility
Don't choose to reinstall MacOS just now, this will simply reinstall the current version of MacOS you currently are on. We have to tweak some settings first. From the top bar, select Utilities / Startup Security Utility.
If secure boot is enabled, you will have to disable it and enable external boot by clicking the radio button next to external boot. Check all options inside external boot. External Boot must be enabled to allow USB or Internet Recovery.
Close the Startup Security Utility, you will be redirected back to the Recovery Menu. Click Disk Utility. If it is not visible, select it from the menu bar at the top Utilities / Disk Utility.
In the next window, select the top-level internal drive, generally named as Macintosh HD. You can recognise the drive from its size listed on the right.

Caution: You have to select the entire drive as a whole. There might be 2 sub volumes shown for the Mac's hard drive. You don't have to select the individual volumes, select the drive as a whole, generally it is the first one under the Internal category.

Install a new OS

After selecting Macintosh HD (the top one under Internal that contains the two sub volumes). Click erase. Format it as: -

. Name: Macintosh HD

. Format: APFS

. Scheme: GUID Partition Map (if not shown the Mac handles it out-of-the-box)

Generally, the above options will be entered by default.
Now, when the formatting completes, you will get the same recovery options as before. Instead of Reinstall MacOS, there will be an option to reinstall the most compatible operating system for your mac, something like Reinstall MacOS Sequioa.
If an OS of your choice is not being shown, you have the following options: -

. ⌘R (Command-R): reinstalls the latest MacOS that was previously installed on your Mac.

. ⌥⌘R* (Option-Command-R): upgrades and installs the latest version of MacOS compatible with your Mac (in your case → Sequoia).

. ⇧⌥⌘R (Shift-Option-Command-R): installs the MacOS that originally shipped with your Mac, or the closest version still available.
That's it, you are all set. Select the OS version of your choice. This will download and install the selected operating system on your Mac. It will take some time according to your network bandwidth and hardware.
The Mac will restart automatically once the installation is complete. You'll see the setup assistant, just follow the prompts to set up your system.