Downgrade Samsung Galaxy S21 / S21 Plus One UI 5.1 to 4.0 | Rollback Android 13 to 12

In this rollback guide, we will show you how to downgrade Samsung Galaxy S21 / S21 Plus from One UI 5.1 to 4.0 i.e. from Android 13 to 12. At the time of writing this article, Samsung started rolling the One UI 5.1 based on the Android 13 update for the Samsung Galaxy S21 / S21 Plus users around the globe; many users have already received the latest OneUI 5.1 update. This straightway translates to the fact that the device owners were able to welcome a plethora of new features.

One UI 5.1 is the latest version of Samsung’s mobile user interface, based on the Android 13 operating system. It offers several new features that are designed to make using your phone easier and more efficient.
However, some users still prefer the older OneUI 4.0 over, the newer one. For some, the high degree of customization is too much to deal with. Along the same lines, others have complained of a few bugs and underlying issues. Likewise, some apps are still not compatible with the latest Android update. So if you also face such issues, there’s a handy way out. You could easily downgrade your Samsung S21 / S21 Plus from One UI 5.1 to 4.0 i.e. from Android 13 to 12. Here are the required instructions in this regard.

Samsung Galaxy S21 5G Device Overview:

The Samsung Galaxy S21 features a 6.2-inch Dynamic AMOLED panel with a 120Hz refresh rate. The screen can go all the way up to 1300 nits under extreme sunlight conditions. It has a resolution of 1080 x 2400 pixels and an aspect ratio of 20:9 ratio. With the Samsung S20, we get the Exynos 2100 chip built on a 5nm manufacturing process. It is an octa-core processor with one Cortex-X1 core clocked at 2.9 GHz, three Cortex-A78 cores clocked at 2.8 GHz, and four Cortex-A55 cores clocked at 2.2 GHz.

In terms of optics, we get a rear quad-camera setup consisting of a 12MP primary sensor paired with an f/1.8 lens, a 12MP ultrawide sensor paired with an f/2.2 lens, and a 64MP telephoto sensor paired with an f/2.0 lens. Coming to the front, we get a single 10 MP sensor paired with an f/2.2 lens. The rear setup can capture 8K videos while the front setup is only limited to 4K video recording.

We get a number of options when it comes to storage variants with 128GB, 256GB, and 512GB of internal storage, with 12 GB of RAM for the lower two variants and 16GB of RAM for the top variant. The phone comes with Android 11 out of the box with OneUI skinned on top of it.

.For connectivity, we get Wi-Fi 802.11 a/b/g/n/ac/6, Bluetooth 5.0, GPS, NFC, USB Type-C 3.2, and FM radio. And for the sensors, we get an ultrasonic under-display fingerprint sensor, accelerometer, gyro, proximity, compass, and barometer. In terms of battery, we get a 4,000 mAh cell that supports 25 fast charging. The S21 is available in four color options: Phantom Gray, Phantom White, Phantom Violet, Phantom Pink.

Downgrade Samsung S21 / S21 Plus One UI 5.1 to 4.0 | Rollback Android 13 to 12

The entire instructions have been broken down into separate sections for ease of understanding. Follow along in the exact same sequence as mentioned.

STEP 1: Take a Device Backup

To begin with, take a backup of all the data on your device. This is because the below downgrade process might wipe off all the data.

STEP 2: Install Odin

Next up, install the Odin Tool on your PC. This will be used to install the downgrade firmware onto your device.

STEP 3: Download the Rollback Firmware

Likewise, download the rollback firmware for your device. This will help you to downgrade your Samsung S21 / S21 Plus from One UI 5.1 to 4.0 i.e. from Android 13 to 12. You could download the Android 13 firmware using the Frija Tool or the Samfirm tool. Just make sure to download the firmware corresponding to your region only.

STEP 4: Boot Samsung Galaxy S21 / S21 Plus to Download Mode

Along the same lines, you will have to boot your device to the Download Mode. To do so, Power off your device. Then press and hold the Volume Down + Volume Up together and connect your device to the PC via USB cable. As soon as you see the Download Mode, release all the keys. Finally, use the Volume Up key to select the OK option. That’s it. Your Samsung S21 / S21 Plus will now be booted to the Download Mode.

STEP 5: Downgrade Samsung S21 / S21 Plus One UI 5.1 to 4.0

Now that you have carried out the above four steps, you may start off with the downgrade process.

1. To begin with, extract the downgrade firmware onto your PC. You should get the AP, BL, CP, CSC, and Home CSC files in the .tar.md5 format.
   
2. Then launch the Odin Tool and connect your device to the PC via USB cable. Make sure that it is booted to Download Mode.
3. As soon as the connection is established, Odin’s ID: COM port will be highlighted. This means that the tool has successfully identified your device in the Download Mode.
   
4. It’s now time to load the firmware files to Odin. So first of all, click on the tool’s BL button and load the BL firmware file.
5. Likewise, do the same for the AP, CP, and CSC. Do keep in mind that you should load the Home CSC file and not the normal one under the CSC section.
6. Once you have loaded all the firmware files, go to the Options section of Odin. Now enable the ‘Auto Reboot’ and ‘F.Reset Time’ options.
   
7. When that is done, hit the Start button and wait for the installation to complete.
8. Once done, the tool will display the PASS message and your device will reboot to the Android 12 OS.
   
9. You may now disconnect the device from the PC and close the Odin Tool.

That’s it. These were the steps to downgrade your Samsung Galaxy S21 / S21 Plus from One UI 5.1 to 4.0 i.e. from Android 13 to 12. If you have any queries concerning the aforementioned instructions, do let us know in the comments section below. Rounding off, here are some equally useful iPhone Tips and Tricks, PC tips and tricks, and Android Tips and Tricks that deserve your attention.