How to Downgrade Samsung Galaxy S21 to One UI 3.1 based on Android 11?

In this guide, we will walk you through the step-by-step process of downgrading your Samsung Galaxy S21 to One UI 3.1 based on Android 11. Whether you are experiencing issues with the latest One UI 4.0 update or simply prefer the previous version, this tutorial will help you revert to the previous operating system. Before we begin, it’s important to note that downgrading your device will result in a factory data reset, meaning all your data will be deleted. So, be sure to back up all your important data before proceeding.

Requirements for Downgrading

Before you start the downgrade process, there are a few requirements that you need to fulfill:

1. Download ODIN: ODIN is a firmware flashing tool that you will need to flash the firmware files onto your device. Make sure to download the latest version of ODIN on your computer.
2. Download One UI 3.1 Firmware File: You will also need to download the One UI 3.1 firmware file for your specific Samsung Galaxy S21 model. It’s important to download the exact firmware file that matches the version number of the firmware you are currently on.
3. Enable Download Mode: You will need to boot your device into Download Mode in order to flash the firmware files. If you are not familiar with this process, refer to our guide on how to boot your Galaxy S21 into Download Mode.
4. USB Connection: Connect your device to your computer via USB while your device is in Download Mode. Make sure that the proper USB drivers are installed on your computer. If the drivers are missing, you can update or install them.

Step-by-Step Guide

Now that you have fulfilled the requirements, let’s proceed with the step-by-step guide to downgrade your Samsung Galaxy S21:

1. Factory Data Reset: If you are experiencing issues with the new update, it’s recommended to factory data reset your device before downgrading. This may resolve any problems you are facing. However, keep in mind that this will delete all your data, so make sure to back it up beforehand.
2. Extract Firmware Files: Once you have downloaded the One UI 3.1 firmware file and ODIN on your computer, extract the firmware file to a location of your choice.
3. Open ODIN: Open ODIN on your computer and ensure that it recognizes your device. If it doesn’t recognize your device, try reconnecting it and make sure you have the proper USB drivers installed.
4. Load Firmware Files in ODIN: In the firmware folder that you extracted earlier, you will find multiple files. Load these files into ODIN as follows:

• Click on the BL button in ODIN and select the file that starts with “BL” from the firmware files.
• Click on the CP button and select the file that starts with “CP”.
• Click on the CSC button and select the file that starts with “CSC”.
• Finally, click on the AP button and select the file that starts with “AP”. This file may take some time to load, so be patient.

Start the Flashing Process: Once you have loaded all the firmware files in ODIN, click on the Start button at the bottom of the screen to begin the flashing process. ODIN will start flashing the firmware files onto your Samsung Galaxy S21. This process may take some time, so do not interrupt it.

Device Restart: Once the flashing process is complete, your device will restart on its own. It will boot back into Android 11, and the boot process may take some time as it is the first time booting into the downgraded operating system.

Verify Android Version: After your device has booted back into Android, go to the About page of your device to check the Android version. It should now show that you are running Android 11.

Congratulations! You have successfully downgraded your Samsung Galaxy S21 to One UI 3.1 based on Android 11. You can now enjoy the previous version of the operating system on your device.

Remember, downgrading your device will result in a factory data reset, so make sure to back up all your important data before proceeding with the tutorial. If you encounter any difficulties during the process, refer to our “How To” page for solutions to common issues.

Additional Tips and Recommendations

• It’s essential to download the correct firmware file for your specific device model and the version number of the firmware you are currently on. Using the wrong firmware file can lead to issues or even brick your device.
• Before downgrading, it’s a good idea to research and read user experiences and feedback about the specific firmware version you plan to downgrade to. This will give you an idea of any potential issues or improvements you can expect.
• Keep in mind that downgrading your device may temporarily remove any new features or improvements introduced in the latest update. Consider the pros and cons before making the decision to downgrade.
• If you are unsure about any step in the process or encounter any difficulties, it’s always recommended to seek assistance from official support channels or knowledgeable forums.

With this guide, you should be able to successfully downgrade your Samsung Galaxy S21 to One UI 3.1 based on Android 11. Enjoy your device with the previous operating system version and the features it offers.

Experiencing difficulties with your Device, check out our “How To” page on how to resolve some of these issues.