: Ensure your phone has at least 60% battery capacity . A sudden shutdown mid-flash will permanently hard-brick your hardware.
Download and install the official utility tool. Open the newly installed Local Update app.
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
Install and open the Local Update APK you downloaded. Select the Firmware: Tap the gear icon (settings) in the top-right corner.
: This downgrade process will completely erase all internal storage, including apps, photos, contacts, and messages. You must back up your files to a computer or cloud service first. : Ensure your phone has at least 60% battery capacity
Paste the file directly into the of your phone's internal storage. Do not place it inside any folder (like Download or Documents ). Step 3: Trigger the System Downgrade
Once you reach the home screen, navigate to . Open the newly installed Local Update app
Once on Android 11, apply these to prevent forced updates:
Flash sequence (order matters):
The decision to downgrade is a personal one. It's a powerful option for fixing problems, but it comes with risks like data loss and potential errors. This guide equips you with the knowledge to make an informed decision. If you choose to proceed, follow the steps for the method that feels most comfortable and always prioritize backing up your data. Good luck!
Starting with OxygenOS 12, the local upgrade option is hidden or removed. You will need to install a dedicated “Local Update” APK to enable the downgrade interface.