To downgrade your OnePlus 9 to Android 11, you'll need to follow these steps:
Modern OxygenOS versions stripped out the native "Local Upgrade" option from the system settings menu. You must sideload the official standalone app to patch this capability back in.
Before beginning any downgrade procedure, you complete these three essential steps: downgrade oneplus 9 to android 11 exclusive
Before you start, please make sure you have the following in place:
Connect your OnePlus 9 to your computer via USB (select mode on your phone notification panel). Cut or copy the downloaded rollback .zip file. Open your phone's internal storage directory on your PC. To downgrade your OnePlus 9 to Android 11,
Downgrading your OnePlus 9 to Android 11 (OxygenOS 11) will restore your phone to its original, fluid software state. This guide provides the official, safest method to roll back your device. Pre-Downgrade Checklist (Crucial Step)
: Download the "MyApplication2" or "OnePlus Local Update" APK. This tool allows you to manually select the rollback file. Prepare the Files : Cut or copy the downloaded rollback
Once installed, open the app and look for the in the top-right corner. 3. Initiate the Rollback
Bricked phones or complete clean flash to Android 11.