How to Install Stock ROM on Samsung SM-G991U (Firmware Guide)

On this page, we have shared the download link and guide to install the Samsung SM-G991U (Galaxy S21 5G) firmware flash file using the Samsung Flash Tool (Also known as Odin Flash Tool). Here you will find all stock firmware zip files for all the supported carriers with Samsung SM-G991U.

If you are someone who wants to restore the device back to factory firmware, then this guide is for you. By using this guide, you can fix certain software-related issues such as hard brick, soft brick, WiFi, or Bluetooth issue, fix lag or stutter or even you can downgrade the device anytime.

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.

Samsung Galaxy S21 5G SM-G991U Firmware Files:

Steps to Flash Stock ROM File on Galaxy S21 5G SM-G991U

Before we get straight to the steps to Install Stock Firmware on your Samsung Galaxy S21 5G, let us take a look at the pre-requirements first.

Pre-Requirements: 

• This Guide is for Samsung Galaxy S21 5G SM-G991U
• You need a Windows PC/Laptop and a USB cable to flash the firmware.
• Charge your device with a minimum of 50% battery backup.
• You have to download the latest Samsung USB Drivers and install them on your PC.
• Make sure that you have ODIN Software installed on your PC.
• Take a backup of your device (No Root) before doing anything.

Now, let’s take a look at Steps to flash Stock ROM on Samsung Galaxy S21 5G.

1. Download the Samsung SM-G991U flash file
2. Extract the contents of the firmware flash file zip.
3. Launch the ODIN application
4. Load the firmware files in their appropriate section
5. Once you have loaded, now connect your phone to the computer (make sure to boot your device into download mode)
6. Notice that the CO port will light up on Odin once you connect your phone.
7. Click the Start button to install the firmware on your Samsung device.
8. That’s it! You will see a PASS message once the installation is complete.

Follow Complete Guidelines

Check out our full depth video guide as well.

Video Tutorial To Install Firmware

We hope that this guide will be helpful to you. If in case, you’re facing any issues, feel free to ask in the comments below.