Downgrading OnePlus 9 to Android 11: A Step-by-Step Guide
While the OnePlus 9 initially received praise for its flagship performance, many users eventually found that newer updates—specifically Android 12 and 13—introduced bugs, battery drain, or UI changes that felt less "OxygenOS" and more like Oppo's ColorOS. If you're missing the stability and sleekness of the original software, this guide will walk you through how to downgrade your OnePlus 9 to Android 11 (OxygenOS 11). Important: Read Before Proceeding Downgrade Oneplus 9 To Android 11
No, if:
Battery Level: Ensure your device has at least 30% battery to prevent it from shutting down mid-process. Downgrading OnePlus 9 to Android 11: A Step-by-Step
How to Downgrade Your OnePlus 9 to Android 11 (OxygenOS 11) If you've updated your OnePlus 9 to Android 12 or 13 and found it buggy or simply prefer the classic OxygenOS experience, you can roll back to Android 11. This process is official but will completely wipe your phone, so a full backup is essential before starting. Prerequisites Open Settings > System > System Updates
If running OxygenOS 12/13:
If you are on Android 12/13, the standard "Local Upgrade" option is often hidden.