Once the installation reaches 100%, tap Reboot . The device will boot into recovery, perform a factory reset, and then start up with OxygenOS 11. Phase 3: Alternative Method (MSM Download Tool)
While newer Android updates introduce cosmetic changes, many users experience significant thermal throttling, battery drain, and bugs. Rolling your device back to Android 11 (OxygenOS 11) restores the clean, lightweight, and blazing-fast user interface that made the phone a flagship killer.
You must download the rollback firmware that matches your specific region (IN, NA, or EU). 2. Required Files downgrade oneplus 9 to android 11 exclusive
Go to > About Phone > Tap Build Number 7 times to enable Developer Options. Go back to Settings > System > Developer Options . Find Automatic System Updates and toggle it OFF .
Tap seven times consecutively until a toast message says, "You are now a developer." Once the installation reaches 100%, tap Reboot
: If your phone becomes unresponsive or "bricked," you may need to use the MSM Download Tool on a PC to force-flash the original firmware. Verification : After the first boot, go to Settings > About Phone to confirm you are on Android 11. for your region's rollback package? Oneplus 9 Pro | Downgrade to OXYGEN OS 11
: If the downloaded file ends in .jar , rename it to .zip before proceeding. 2. Install the Local Update APK Rolling your device back to Android 11 (OxygenOS
OxygenOS 11 maintains the "classic" OnePlus look, whereas Android 12 adopts Oppo’s ColorOS design. Stability: Users report significantly fewer bugs and smoother performance on Android 11. Customization: