Monterey to BigSur

harryjjames wrote:

I upgraded to macOS Monterey from BigSur and was wondering if I could downgrade back to macOS BigSur.

Im probably really dumb since I didn't make a time machine back up

Revert your Mac to a previous macOS version
https://support.apple.com/en-lamr/guide/mac-help/mh15216/10.15/mac/10.15

How to erase your Intel-based Mac - https://support.apple.com/en-us/HT208496

How to reinstall macOS from macOS Recovery - https://support.apple.com/en-us/HT204904

https://beta.apple.com/sp/betaprogram/restore#macos

https://beta.apple.com/sp/betaprogram/unenroll#macos

First copy any files you want to save to another drive then go to Recovery, erase your drive and reinstall the OS. Then you can copy back your saved files. You will have to reinstall any apps you had one by one since you had no backup prior.

A time machine backup does not really help in restoring an older system on top of a new one, unless the backup was done before you installed the newer system.

You shouldn't be beta testing without a backup. Unless of course you have no value for your data. Music and Photo libraries get upgraded with each operating system upgrade. A beta should never be used as a production system. Once those libraries are upgraded, they are impossible to downgrade without losing information such as albums, playlists, keywords, and custom date and names for anything you created custom. Stuff in the Online Music store can always be redownloaded.

Carbon Copy Cloner is a safer bet when beta testing. Because then you have better version control of different clones you can make to separate partitions. Automatic Time Machine backups can erase intermediate backups when your backup drive gets too full