Downgrading Catalina to High Sierra

[freebrian]

Has anyone done a downgrade from Catalina to High Sierra on a mac with an internal SATA disk (not SSD)? I would like to know how successful you were and why you chose to downgrade.

My disk cannot tolerate Catalina but a few days ago it was fine on High Sierra for basic things. I want to go back.

Steps I am taking:
1. I am downloading the High Sierra disk image from the app store right now.

2. I will finish copying my data files to external drives for backup.

3. I will try to make a bootable installation USB.

4. Then, I will try to erase the internal drive and format it to HFS+ instead of the APFS format that Catalina automatically converted it to.

5. Then I will try to install macOS High Sierra from the USB.


Do I want to use Migration Assistant with this? I've never touched that. I plan on having to reinstall all my apps pretty much one by one but if anyone has a better idea tell me. I have installation files for some of them which I can back up.

(Please do not make hardware upgrade suggestions on this thread, I'm already discussing that and working that out somewhere else. I am convinced I do not want Catalina for now.)

 

[rm5]

I chose to downgrade way back when because of the lack of 32-bit app compatibility, and because Catalina was so slow on the spinning drive.

Your plan sounds good, that'll work perfect! Migration Assistant should work just fine--you just need a Time Machine backup to use to restore the files. If you don't have one or don't want to make one, just copying the files in Finder is also fine.