Last Updated: June 3, 2026
Restoring your SM-G998W Galaxy S21 Ultra 5G is a simple process when you use the official Samsung Galaxy S21 Ultra 5G SM-G998W firmware. This page contains all the necessary files and instructions for hard resets, FRP bypass, IMEI repair, and complete flashing.
Device: Samsung Galaxy S21 Ultra 5G SM-G998W | Chipset: Qualcomm Snapdragon 888 5G SM8350 | Flash Tool: Odin
Android: Android 11, One UI 3.1 | File Type: .tar.md5 / ZIP (Contains AP, BL, CP, CSC files for Odin)
⚠ Warning: Flashing erases all data. Back up first.
Samsung Galaxy S21 Ultra 5G SM-G998W Firmware (Flash File) Drivers, Tools & Guide
Installing the official software on your Samsung Galaxy S21 Ultra 5G SM-G998W requires Odin, the correct drivers, and the exact firmware files. Using Odin to flash a phone is a manageable process if you prepare correctly. I have organized the exact files and steps on this page to help you complete the job without confusion.
Before you begin, ensure you sign out of any active Samsung accounts. Skipping this step can trigger a Knox security lock, which adds unnecessary time to your repair. You will also want to check the contents of your downloaded firmware. Samsung packages arrive in a .tar.md5 format. Once you extract the main ZIP folder, look for files labeled AP, BL, CP, and CSC.
You can use WinRAR or 7-Zip to extract your Samsung Galaxy S21 Ultra 5G SM-G998W firmware package. Inside the folder, you should see files such as AP_*.tar.md5, BL_*.tar.md5, CP_*.tar.md5, and CSC_*.tar.md5 (or HOME_CSC_*.tar.md5). If these specific files are missing, you likely downloaded the incorrect package for your phone.
Remember that installing stock software will completely wipe your phone. This factory reset effect is exactly what resolves persistent software glitches, including FRP locks, system lag, forgotten passwords, bootloops, and connectivity bugs.
Hard Reset Samsung Galaxy S21 Ultra 5G SM-G998W
You can factory reset the Samsung Galaxy S21 Ultra 5G SM-G998W without a computer by holding the Volume Up + Power buttons together until the recovery menu loads, then selecting “Wipe Data/Factory Reset” (for older models with a Home button, use Volume Up + Home + Power). Use the volume keys to navigate the menu and the power button to confirm your choice.
Performing a hard reset returns the Samsung Galaxy S21 Ultra 5G SM-G998W to its factory defaults by erasing all user data. This step clears up common performance drops, application crashes, and forgotten screen locks. If a simple reset does not solve the problem, the full Odin installation below is your next step.
Samsung Galaxy S21 Ultra 5G SM-G998W FRP Bypass
The most effective way to bypass FRP on the Samsung Galaxy S21 Ultra 5G SM-G998W is by using a free launcher tool to access settings during the initial setup. After a factory reset or a flash, your phone might ask for the previously synced Google account details. You can use our free Android apps launcher to navigate past this lock. Removing your Google account before wiping the phone is always the best practice to prevent this situation entirely.
Why Do We Need Samsung Galaxy S21 Ultra 5G SM-G998W Firmware?
Flashing the official Samsung Galaxy S21 Ultra 5G SM-G998W firmware is necessary to repair severe software issues, update the operating system, or restore the device to its original factory state. Samsung phones are flashed using the Odin utility, regardless of the internal processor. Installing the official software resolves a wide range of system errors:
- Unlock a disabled or locked handset.
- Install the newest Android version approved for your hardware.
- Clear persistent freezing, lag, and continuous bootloops on your SM-G998W Galaxy S21 Ultra 5G.
- Fix battery draining problems and failed over-the-air updates.
- Reinstall the original stock ROM to maintain your warranty status.
- Repair a phone that will only boot into the recovery menu.
- Fix KG lock or Knox errors caused by a previous interrupted installation.
You can learn more about stock ROMs and why flashing works.
Choosing the Right Firmware Version
Selecting the correct firmware version for your Samsung Galaxy S21 Ultra 5G SM-G998W requires verifying your exact model number, region code, and binary level. Taking a few minutes to confirm your files prevents major installation errors:
- Identify Your Exact Model Number: Open Settings › About Phone and verify your model is SM-G998W. The final letter dictates the region (U/U1 for USA, W for Canada, N for Korea, B/F for International). Using a file meant for another region will cause errors.
- Match the CSC (Region): The firmware filename contains a 3-letter region code that must match your device. You can find your current CSC in Settings › About Phone › Software Information or on the Download Mode screen. Examples include XAA (US), BTU (UK), INS (India), and SER (Russia).
- Check the Binary Level: Look at your current software version string (for example,
XXU9BZDP). The number indicates the binary level. You are not allowed to downgrade past your current binary. A phone on Binary 9 requires Binary 9 or higher. - Confirm the Build Date: The final 4 characters of the PDA version show the build date. The first letter is the year (A=2024, B=2025, C=2026), and the second is the month (A=January through L=December).
- Verify in Download Mode: Power down the phone and hold Volume Down + Power to open Download Mode. This screen lists your exact model, CSC, and software version for final confirmation.
Firmware Details for Samsung Galaxy S21 Ultra 5G SM-G998W
The official firmware specifications for the Samsung Galaxy S21 Ultra 5G SM-G998W include Android 11, One UI 3.1, and the Qualcomm Snapdragon 888 5G SM8350 chipset. Here is a quick look at the official software details:
| Firmware Information | Details |
|---|---|
| Device Model | Samsung Galaxy S21 Ultra 5G SM-G998W |
| Firmware Version | N/A |
| File Size | N/A |
| Android Version | Android 11, One UI 3.1 |
| Platform | Qualcomm Snapdragon 888 5G SM8350 |
| Release Date | Released 2021, January 29 |
| Region | Global, Africa and Asia |
| File Type | .tar.md5 / ZIP (Contains AP, BL, CP, CSC files for Odin) |
Which Firmware Version Should I Download?
You should download the firmware version that matches your specific repair scenario, binary level, and regional CSC code. I receive many questions about file selection, so I created this reference table. Find your current situation to identify the correct file:
| Your Situation | What I Recommend |
|---|---|
| Phone is completely dead or stuck on logo | the latest version, download this one. It is the newest Samsung Galaxy S21 Ultra 5G SM-G998W firmware available. |
| FRP / Google account lock only | See the FRP bypass guide above, you likely do not need the full firmware for this. |
| Not sure which region/CSC to download | Check Settings › About Phone › Software Information for your current CSC, or enter Download Mode (Volume Down + Power), it shows the CSC on screen. Match the 3-letter code (e.g. XAA, BTU, INS) to the firmware filename. |
| Phone slow after a recent OTA update | Try the next older version, sometimes the latest OTA introduces new bugs and an older build runs better. Make sure the binary level is the same or higher than what your device currently has. |
| IMEI missing after a previous flash | Re-flash the latest version first, then follow the IMEI repair guide. Do not skip the reflash. |
| the latest version failed with a flash error | Try the next older version instead and double-check your AP/BL/CP/CSC file assignments in Odin before assuming the firmware is the problem. |
| Restoring to factory / warranty repair | the latest version, clean state, fresh start. |
To tell which Samsung firmware is newer, look at the last 4 characters of the PDA version string (e.g. S938BXXU9CZDP). The first character is the year (A=2024, B=2025, C=2026), the second is the month (A=Jan, B=Feb… L=Dec, Z=final stable), and the last two are the revision (0-9 then A-Z, where Z is highest). But before comparing dates, always check the binary level: the digit just before the date code (e.g. XXU9CZDP = Binary 9). You cannot downgrade to a lower binary level. If your device is on Binary 9, only flash Binary 9 or higher. Also make sure the 3-letter CSC code in the firmware matches your device region.
Download Samsung Galaxy S21 Ultra 5G SM-G998W Firmware
You can download the official stock software for your Samsung Galaxy S21 Ultra 5G SM-G998W directly from the links provided below. The most recent release is the latest version. Once the download finishes, compare the file size against the specifications table. A mismatched file size often indicates a corrupted download, which can cause severe errors during installation.
Always ensure the file matches your exact hardware. See the firmware selection guide above if you are not sure.
- Your model number is a variant of SM-G998W with a different letter suffix. Check About Phone carefully, one letter difference can cause a failed or broken flash.
- Your chipset differs from Qualcomm Snapdragon 888 5G SM8350. Confirm in recovery mode before proceeding.
- You downloaded the file from a source other than this page.
- The file size differs significantly from the sizes listed in the table above, a size mismatch usually means a partial download, which will fail mid-flash.
Prerequisites for Samsung Galaxy S21 Ultra 5G SM-G998W Firmware
Preparing to flash the Samsung Galaxy S21 Ultra 5G SM-G998W firmware requires backing up your data, removing accounts, and installing the correct USB drivers. Review this checklist before launching Odin. Two common mistakes cause the most issues: leaving a Samsung account signed in (which triggers KG lock) and using a low-quality USB cable that disconnects during the process. Always use a high-quality data cable.
- Back Up IMEI Numbers: Dial *#06# and write down both IMEI numbers now. You will need these if you need to restore your IMEI after flashing.
- Remove Google Accounts: Sign out of all Google accounts to prevent FRP lock after flashing.
- Remove Samsung Accounts: Sign out of all Samsung accounts to avoid KG lock.
- Back Up Your Data: Back up everything, photos, contacts, WhatsApp chats, important files. Flashing wipes the device completely.
- Charge Your Device: At least 50% battery. A device that powers off during a flash is very difficult to recover.
- USB Cable & PC: Use a proper data USB cable, not a charge-only cable, and a Windows computer with available USB ports.
- Install Required Drivers:
How to Install Firmware on Samsung Galaxy S21 Ultra 5G SM-G998W
Installing the firmware on your Samsung Galaxy S21 Ultra 5G SM-G998W involves using the Odin flash tool to load the AP, BL, CP, and CSC files onto the device. We will use Odin for this procedure. Leave the “Auto Reboot” and “F. Reset Time” boxes checked in Odin to ensure a clean installation. If you need help picking a version, visit our Odin versions page. Older phones occasionally require older Odin builds.
- Download and Extract:
- Download the correct software package and extract the ZIP folder to a simple directory path. Avoid folder names with spaces or special characters.
- Install the Listed Drivers:
- Ensure all drivers listed above are installed and restart your computer. Skipping the restart can prevent the drivers from functioning properly.
- Load the Firmware File:
- In the Odin interface, click “BL” and select the BL_*.tar.md5 file. Click “AP” and select the AP_*.tar.md5 file. Repeat this for “CP” and “CSC”. Select HOME_CSC if you want to keep your data, or standard CSC for a complete wipe.
- Connect Your Device:
- Enter Download Mode by turning off the phone and holding Volume Down + Power (add the Home button on older models) until the warning screen appears. Press Volume Up to proceed.
- Connect the phone to your PC. Odin will display “Added..” in the log box when the connection is successful.
- Start Flashing:
- Click the “Start” button. Leave the phone completely alone until the process finishes. Unplugging the cable mid-flash will damage the device.
- Wait and Reboot:
- Disconnect the phone once Odin shows a successful result. Turn the device on. The initial startup sequence takes longer than usual, often up to 8 minutes.
Video Guide for Flashing
What to Expect After Flashing Samsung Galaxy S21 Ultra 5G SM-G998W Firmware
After flashing the Samsung Galaxy S21 Ultra 5G SM-G998W firmware, you should expect a longer first boot time, warm device temperatures, and a complete wipe of your personal data. Many users worry that the installation failed when the phone behaves differently immediately afterward. Here is what is completely normal:
- How to know the flash was successful: Odin will display “PASS.” in a green box. Seeing this means the installation completed properly.
- First boot takes 3 to 8 minutes, do not restart the phone manually. The system is configuring itself for the first time. Interrupting this phase can cause a bootloop.
- The phone will feel warm during first boot, this is standard behavior. The temperature will return to normal shortly after the setup finishes.
- All your apps are gone, a flash completely clears your storage. You will need to download your applications again from the Play Store.
- Dial *#06# immediately after setup to verify your IMEI number before inserting a SIM card. If the screen displays “unknown” or “null”, follow the IMEI repair guide right away.
- Be careful when re-adding your Google account, if you forgot to remove your account prior to flashing, you might encounter an FRP prompt. Enter your details through the initial setup wizard rather than the settings menu.
- Wi-Fi, Bluetooth, and mobile data should function normally right away. If mobile data fails, navigate to Settings › SIM and Network to manually input your APN details, as the flash sometimes deletes carrier configurations.
- Stuck in a bootloop after first boot? Access recovery mode and perform a factory reset from that menu. Review the hard reset guide above. This occasional glitch usually stems from leftover data conflicts, not a bad file.
- Samsung Smart Switch: Following a successful Samsung Galaxy S21 Ultra 5G SM-G998W firmware installation, Smart Switch might suggest additional updates. Allow the application to install them to guarantee your phone has the correct security patches for your region.
Missing IMEI or Corrupt Baseband on Samsung Galaxy S21 Ultra 5G SM-G998W After Flashing?
A missing IMEI or corrupt baseband on the Samsung Galaxy S21 Ultra 5G SM-G998W usually indicates a wiped or damaged EFS partition that requires specific repair tools. The EFS partition holds your IMEI and network data. Be aware that writing a fake IMEI is illegal in many areas, so only restore the original number that came with your phone. Software like ChimeraTool or BFT can assist with this repair. Verify your local regulations first.
Video Guide: How to repair IMEI
Common Issues When Flashing Samsung Galaxy S21 Ultra 5G SM-G998W
- Odin Shows “FAIL” Instead of “PASS”:
- This error typically occurs when the software does not match your exact model or region. Double-check your model number in Settings › About Phone before trying again.
- Samsung Galaxy S21 Ultra 5G SM-G998W Not Recognized by Odin:
- Reinstall the Samsung USB drivers and confirm the phone is actually in Download Mode. Switching to a different USB cable often resolves connection drops.
- KG Lock / Knox Triggered After Flashing:
- This security measure activates when a Samsung account remains logged in before a flash, or if unofficial software is installed. Removing accounts beforehand prevents this. If it is already triggered, you generally need a professional unlocking service.
- Boot Loop After Flashing:
- Open recovery mode by holding Volume Up + Power and execute a factory reset. This deletes conflicting temporary files left over from the previous system.
Frequently Asked Questions
Q1: Will flashing the Samsung Galaxy S21 Ultra 5G SM-G998W firmware erase my data?
A: Yes, installing this software with Odin completely wipes the phone and loads the default Android 11, One UI 3.1 environment. Every app, photo, contact, and account will be permanently deleted. Save your files beforehand, as recovery is impossible after the process finishes.
Q2: Is this firmware compatible with other Samsung models?
A: No, this specific package is designed exclusively for the Samsung Galaxy S21 Ultra 5G SM-G998W equipped with the Qualcomm Snapdragon 888 5G SM8350 processor. Even a slightly different model variant can feature entirely different internal hardware. Installing the wrong file can severely damage your phone. Always verify your exact model in Settings › About Phone.
Q3: Can I downgrade from the latest version to an older firmware version?
A: While sometimes technically possible on Qualcomm devices, rolling back is generally unadvisable. Downgrading can introduce security vulnerabilities and break app compatibility on Android 11, One UI 3.1. If the newest release is malfunctioning, leave a comment below so we can troubleshoot the actual issue.
Q4: What should I do if I encounter an FRP lock after flashing?
A: You can use our free Android apps launcher to bypass the lock. FRP triggers on the Samsung Galaxy S21 Ultra 5G SM-G998W when a Google account remains logged in prior to flashing. Logging out of your accounts before starting the flash is the easiest way to avoid this hurdle.
Q5: Are custom ROM options available for the Samsung Galaxy S21 Ultra 5G SM-G998W?
A: This tutorial focuses entirely on official Samsung stock software. The availability of custom ROMs for the Samsung Galaxy S21 Ultra 5G SM-G998W relies on whether developers offer open-source kernel support for the Qualcomm Snapdragon 888 5G SM8350. You can check our Custom ROMs page or the XDA Developers forum for community-built alternatives.
Q6: My Samsung Galaxy S21 Ultra 5G SM-G998W is not detected by Odin. What should I do?
A: Begin by reinstalling the Samsung USB drivers and rebooting your computer. Try moving the cable to a USB 2.0 port instead of a USB 3.0 port, as Samsung devices often communicate more reliably on the older standard. Temporarily disable your antivirus software. If the problem persists, leave a comment with the exact error message for further assistance.
Q7: How do I enter recovery mode on my Samsung Galaxy S21 Ultra 5G SM-G998W?
A: Turn the phone off entirely, then press and hold Volume Up + Power simultaneously until the recovery menu opens. On older Samsung phones featuring a physical Home button, press Volume Up + Home + Power. The recovery screen displays the build number for your Samsung Galaxy S21 Ultra 5G SM-G998W, which helps you confirm your current software version.
Q8: My IMEI shows “unknown” after flashing the Samsung Galaxy S21 Ultra 5G SM-G998W. Is my phone permanently damaged?
A: No, the phone is not ruined, and the issue is repairable. Follow the instructions in the IMEI repair guide located in the section above. Check the EFS partition for corruption first. Wait to insert your SIM card until after the IMEI is fully restored.
Q9: How long does it take to flash Samsung Galaxy S21 Ultra 5G SM-G998W firmware?
A: The Odin installation generally requires 3 to 10 minutes, depending on the file size and your USB transfer speed. The first startup sequence takes an additional 3 to 8 minutes. Do not unplug or restart the phone during either phase. If the Odin progress bar appears frozen, wait a few extra minutes before taking action.
Final Thoughts on Samsung Galaxy S21 Ultra 5G SM-G998W Firmware
Following these instructions carefully will help you successfully install the official Samsung Galaxy S21 Ultra 5G SM-G998W firmware and restore your device to proper working order. If you followed the preparation steps and the Odin guide, your phone should now boot into a fresh, clean system.
If you ran into an error or a specific step did not work, please leave a comment below. Include the exact error message, your current step, and the troubleshooting methods you have already attempted. I read every comment and will provide guidance.
If you found this tutorial helpful, please share it with others who might need assistance with their phone.
Browse all Samsung firmware downloads for more devices.
Disclaimer: Flashing stock firmware is performed at your own risk. Follow the instructions on this page carefully. I cannot be held responsible for any damage to your device, but I will always try to help if something goes wrong.
