If the rollback file is in .jar format, rename it to end in .zip .
To prevent your OnePlus 9 from immediately re-downloading Android 12 or 13, you need to turn off automatic background updates. Navigate to .
Ensure your device has at least 50% charge to prevent it from shutting down mid-process.
This tool allows you to flash the package. Backup Data: Move all important files to a computer. Step-by-Step: Downgrade OnePlus 9 to Android 11
or 9 Pro) and region from sources like the OnePlus Community forums or SourceForge . Find the downloaded file in your file manager. If it ends in .jar , rename it to end in .zip . downgrade oneplus 9 to android 11 exclusive
OnePlus phones come in several regional variants: . Downloading the wrong rollback package for your region can brick your device. As a T-Mobile community expert warns, “always use the toolkit for YOUR device model — for they are not interchangeable. You will get a failed result EVERY TIME”.
Move the rollback .zip file to the of your phone's internal storage (do not put it in any folder). Phase 2: Execution (Local Upgrade Method) This is the standard official method for a working device.
Before downgrading your OnePlus 9 device to Android 11, make sure to:
Navigate to the home screen (this is the "root" directory). If the rollback file is in
Once you are on OxygenOS 11, the phone may immediately ask to update back to Android 12/13.
Ensure you download the rollback package that matches your specific regional hardware model (e.g., North America, Europe, or India). Installing the wrong regional firmware can cause network connectivity issues. Step 1: Back Up Your Data
Extract the downloaded firmware using password: . Open the firmware folder where you extracted the files.
Click to begin the process. The system will now wipe your device and flash Android 11. Ensure your device has at least 50% charge
If the app shows as a .zip , rename it to .apk to install it. Open the installed Local Update app. Tap the gear icon in the top right corner. Select your downloaded .zip rollback package.
The installation method varies depending on which version of Android you are currently running. Method A: If you are running Android 12 Go to . Tap the Gear Icon located in the top right corner. Select Local Upgrade .
You must download the rollback firmware that matches your specific region (IN, NA, or EU). 2. Required Files
Look for the stable OxygenOS 11 zip specifically labeled for model LE2115 .
For complete control, use ADB commands: