Downgrade OnePlus 9 to Android 11: Comprehensive Step-by-Step Guide
Before we dive into the process, it's essential to understand why someone might want to downgrade their OnePlus 9 to Android 11:
Double-check that you downloaded the correct regional package for your specific Go to product viewer dialog for this item. model (e.g., LE2115 for NA).
This happens if the firmware file resides inside the "Downloads" folder. Move the .zip file out of all folders and place it directly into the "Internal Storage" directory. Downgrade Oneplus 9 To Android 11
Complete the initial Android setup wizard without signing into everything immediately if you want to verify system stability first.
Use the original OnePlus Red Cable or a high-quality USB data cable to connect to your computer if needed.
Wait for the installation progress bar to hit 100%. Do not turn off your phone. Tap once the system installation finishes. Method B: For OnePlus 9 on Android 13 Move the
Open your computer or mobile browser and navigate to the official OnePlus Community forums or trusted firmware repositories (like OxygenOS Updater or XDA Developers) hosting official OnePlus firmware links.
After downgrading to Android 11, keep in mind:
Tap the 7 times rapidly until a toast notification says, "You are now a developer." Step 4: Flash the Android 11 Firmware Wait for the installation progress bar to hit 100%
Download and install the official tool. Open the newly installed Local Update app. Tap the gear icon in the top right corner. Select the rollback ZIP file from your root storage. Confirm the system downgrade. Step 5: Final Reboot and Setup
If the downloaded file ends with .jar , rename it on your computer or phone file manager to end strictly with .zip . Step 3: Prepare the Installation File
. The phone will perform a factory reset and boot into the OxygenOS 11 setup screen. Troubleshooting & Tools