Last Updated: June 3, 2026
Getting your SM-G998N back to working condition requires the official Samsung Galaxy S21 Ultra 5G SM-G998N firmware. This page has every file and step you need to handle hard resets, FRP bypass, IMEI repair, and full flashing.
Device: Samsung Galaxy S21 Ultra 5G SM-G998N | Chipset: Samsung Exynos 2100 5G S5E9840 | 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-G998N Firmware (Flash File) Drivers, Tools & Guide
Flashing Samsung Galaxy S21 Ultra 5G SM-G998N firmware with Odin is a straightforward process when you have the right files and steps. I have gathered everything you need right here: the correct Odin version, the matching flash files, and a reliable set of instructions. If you feel overwhelmed, do not worry, I have been there, and this guide will walk you through it safely.
Before you connect your phone to the computer, make sure to sign out of any active Samsung accounts. Skipping this step triggers Knox security, which adds unnecessary complications. Also, remember that Samsung firmware uses a .tar.md5 format. Once you extract the ZIP folder, look for files labeled AP_*, BL_*, CP_*, and CSC_* (or HOME_CSC_*). If those are missing, the package is incorrect.
Your Samsung Galaxy S21 Ultra 5G SM-G998N firmware arrives as a compressed ZIP archive. Use WinRAR or 7-Zip to unpack it. Inside, you will find the AP_*.tar.md5, BL_*.tar.md5, CP_*.tar.md5, and CSC_*.tar.md5 files. Missing these usually means you downloaded the wrong package for your specific phone.
Keep in mind that installing stock software completely wipes your phone. This factory reset effect is intentional and clears out software glitches, FRP locks, forgotten passwords, bootloops, battery drain, and soft brick errors.
Hard Reset Samsung Galaxy S21 Ultra 5G SM-G998N
You can factory reset the Samsung Galaxy S21 Ultra 5G SM-G998N without a computer by holding Volume Up + Power until the recovery menu loads. For models with a Home button, hold Volume Up + Home + Power. Once the menu appears, use the volume keys to highlight “Wipe Data/Factory Reset” and press the Power button to confirm.
Performing a hard reset completely clears your data and returns the Samsung Galaxy S21 Ultra 5G SM-G998N to its factory settings. This resolves common complaints like sluggish performance, system crashes, and forgotten screen locks. If the phone still acts up after the reset, move down to the full Odin flashing instructions.
Samsung Galaxy S21 Ultra 5G SM-G998N FRP Bypass
The most effective method to bypass FRP on the Samsung Galaxy S21 Ultra 5G SM-G998N involves using a free Android apps launcher to access settings during the initial setup. Following a factory reset or firmware installation, you might encounter a Google account lock (FRP). Our free Android apps launcher handles this quickly. To prevent this hurdle entirely, always remember to remove your Google account before starting the flash process.
Why Do We Need Samsung Galaxy S21 Ultra 5G SM-G998N Firmware?
Flashing the official Samsung Galaxy S21 Ultra 5G SM-G998N firmware is necessary to repair severe software issues, regardless of the internal chipset. If your phone is acting up, installing the stock software usually fixes it. Here are a few reasons to flash:
- Remove locks if the phone is disabled.
- Install the most recent Android version supported by the hardware.
- Stop freezing, lagging, and continuous bootloops on your SM-G998N.
- Fix battery draining quickly or over-the-air update failures.
- Return to the original stock ROM to maintain warranty status.
- Fix a phone that only boots into the recovery menu.
- Clear up KG lock or Knox errors caused by a bad or interrupted flash.
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-G998N is crucial because flashing the wrong file causes serious system errors. Take a minute to verify your files before you begin, as recovering from a bad flash takes a lot of effort:
- Identify Your Exact Model Number: Open Settings › About Phone and check the full model number (e.g. SM-G998N). The letter at the end is important: U/U1 means USA, W means Canada, N means Korea, and B/F means International. Installing a file meant for another region causes problems.
- Match the CSC (Region): The firmware filename includes a 3-letter region code that must match your phone. Find your current CSC under Settings › About Phone › Software Information, or check Download Mode. Common codes include XAA (US), BTU (UK), INS (India), and SER (Russia).
- Check the Binary Level: Look at your current firmware version string (for example,
XXU9BZDP, the number is the binary level). You cannot downgrade past this number. A phone on Binary 9 only accepts Binary 9 or higher. - Confirm the Build Date: The last 4 characters of the PDA version reveal the build date. The first letter is the year (A=2024, B=2025, C=2026), and the second is the month (A=Jan to L=Dec).
- Verify in Download Mode: Turn off the phone, then hold Volume Down + Power to open Download Mode. This screen displays your exact model, CSC, and software version for easy verification.
Firmware Details for Samsung Galaxy S21 Ultra 5G SM-G998N
The official firmware specifications for the Samsung Galaxy S21 Ultra 5G SM-G998N include Android 11, One UI 3.1, and the Samsung Exynos 2100 5G S5E9840 platform. Here is a quick look at the software details:
| Firmware Information | Details |
|---|---|
| Device Model | Samsung Galaxy S21 Ultra 5G SM-G998N |
| Firmware Version | N/A |
| File Size | N/A |
| Android Version | Android 11, One UI 3.1 |
| Platform | Samsung Exynos 2100 5G S5E9840 |
| 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 situation, such as choosing the latest build for a dead phone or an older build if the newest OTA causes lag. People ask me about this all the time in the comments, so I created this reference table. Find your scenario and grab the right file:
| Your Situation | What I Recommend |
|---|---|
| Phone is completely dead or stuck on logo | the latest version, download this one. It is the latest Samsung Galaxy S21 Ultra 5G SM-G998N 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 figure out 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-G998N Firmware
You can download the official Samsung Galaxy S21 Ultra 5G SM-G998N firmware directly from the links provided below. The newest available release is the latest version. Once the download finishes, double-check the file size against the table above. A mismatched file size usually points to a corrupted download, and flashing a broken file creates more issues than it fixes.
Always ensure the software matches your exact model. See the firmware selection guide above if you are not sure.
- Your model number is a variant of SM-G998N with a different letter suffix. Check About Phone carefully, one letter difference can cause a failed or broken flash.
- Your chipset differs from Samsung Exynos 2100 5G S5E9840. 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-G998N Firmware
Preparing the proper drivers, cables, and backups is required before flashing the Samsung Galaxy S21 Ultra 5G SM-G998N firmware. Check these items off your list before launching Odin. Two things cause the most headaches here: forgetting to sign out of your Samsung account (which triggers KG lock) and using a cheap charging cable that drops the connection mid-flash. Always grab a high-quality data cable.
- Back Up IMEI Numbers: Dial *#06# and write down both IMEI numbers. You might need them to restore your connection later.
- Remove Google Accounts: Sign out of all Google accounts to prevent FRP lock.
- Remove Samsung Accounts: Sign out of Samsung accounts to avoid triggering KG lock.
- Back Up Your Data: Save your photos, contacts, and files elsewhere. Flashing deletes everything.
- Charge Your Device: Keep the battery above 50%. A shutdown during a flash is hard to fix.
- USB Cable & PC: Use a reliable data USB cable and a Windows computer.
- Install Required Drivers:
How to Install Firmware on Samsung Galaxy S21 Ultra 5G SM-G998N
Installing the firmware on your Samsung Galaxy S21 Ultra 5G SM-G998N requires the Odin flash tool and careful attention to the AP, BL, CP, and CSC file slots. We are using Odin for this process. Leave “Auto Reboot” and “F. Reset Time” checked in Odin for the best results. If you need help picking an Odin version, visit our Odin versions page. Older phones sometimes prefer older Odin builds.
- Download and Extract:
- Grab the correct firmware package and extract the ZIP into a simple folder. Avoid folder paths with spaces or special characters.
- Install the Listed Drivers:
- Ensure all drivers listed above are installed and restart your computer. Skipping the restart often causes driver failures.
- Load the Firmware File:
- In Odin, click “BL” and select the BL_*.tar.md5 file. Do the same for “AP”, “CP”, and “CSC”. Pick HOME_CSC to keep your data intact, or CSC for a completely clean wipe.
- Connect Your Device:
- Turn off the phone, then hold Volume Down + Power (add the Home button on older models) until the warning screen pops up. Press Volume Up to enter Download Mode.
- Plug the phone into your PC. Odin will display “Added..” in the log when it detects the phone.
- Start Flashing:
- Click “Start” to begin.
- Leave the phone completely alone until the process finishes. Unplugging the cable mid-flash causes severe damage.
- Wait and Reboot:
- Once Odin shows a successful finish, unplug the phone.
- Turn it on. The first startup takes up to 8 minutes, so be patient.
Video Guide for Flashing
What to Expect After Flashing Samsung Galaxy S21 Ultra 5G SM-G998N Firmware
After flashing the Samsung Galaxy S21 Ultra 5G SM-G998N firmware, you will notice a longer initial boot time, missing apps, and a warm device temperature, which are all normal behaviors. I receive many comments from readers who panic because their phone acts a little strange right after a flash. Do not worry, here is what is perfectly normal:
- How to know the flash was successful: A green “PASS.” message in Odin means the installation worked perfectly.
- First boot takes 3 to 8 minutes: The system is rebuilding itself. Do not force a restart, or you might cause a bootloop.
- The phone will feel warm during first boot: This is expected behavior. It will cool down once the initial setup finishes.
- All your apps are gone: This happens during a clean flash. Just download them again from the Play Store. Your Google backup might offer to restore them automatically.
- Dial *#06# immediately after setup: Check your IMEI before inserting a SIM card. If it reads “unknown” or “null”, follow the IMEI repair guide right away.
- Be careful when re-adding your Google account: If you skipped removing the account earlier, you might face an FRP prompt. Add it during the setup wizard rather than through the Settings menu.
- Wi-Fi, Bluetooth, and mobile data: These should work immediately. If mobile data fails, go to Settings › SIM and Network and type in your APN details manually, since the flash sometimes wipes carrier settings.
- Stuck in a bootloop after first boot? Boot into recovery and run a factory reset. Check the hard reset guide above. This clears out leftover files from the old system.
- Samsung Smart Switch: Smart Switch might ask to install extra updates after you flash the Samsung Galaxy S21 Ultra 5G SM-G998N firmware. Allow it to finish so your phone gets the right security patches.
Missing IMEI or Corrupt Baseband on Samsung Galaxy S21 Ultra 5G SM-G998N After Flashing?
A missing IMEI or corrupt baseband on your Samsung Galaxy S21 Ultra 5G SM-G998N usually indicates a corrupted EFS partition that needs restoration. The EFS partition holds your IMEI and network details. Restoring an IMEI that does not belong to your original device is illegal in many areas, so only restore your actual number. Programs like ChimeraTool or BFT can fix this. Check your local regulations first.
Video Guide: How to repair IMEI
Common Issues When Flashing Samsung Galaxy S21 Ultra 5G SM-G998N
- Odin Shows “FAIL” Instead of “PASS”:
- This typically means the firmware region or model does not match your phone. Double-check your model number in Settings › About Phone. A single letter difference matters.
- Samsung Galaxy S21 Ultra 5G SM-G998N Not Recognized by Odin:
- Reinstall the Samsung USB drivers and ensure you are in Download Mode. Try swapping to a different USB cable, as Odin is picky about connection quality.
- KG Lock / Knox Triggered After Flashing:
- This occurs when a Samsung account remained logged in, or unofficial software was installed. Always log out beforehand. If KG lock is active, you generally need a professional tool to clear it.
- Boot Loop After Flashing:
- Open recovery mode (Volume Up + Power) and perform a factory reset. This wipes out conflicting data from the previous installation.
Frequently Asked Questions
Q1: Will flashing the Samsung Galaxy S21 Ultra 5G SM-G998N firmware erase my data?
A: Yes, installing this software with Odin completely wipes the phone and returns it to the default Android 11, One UI 3.1 settings. Every app, photo, and account will disappear. Save your files beforehand, because you cannot recover them after the flash finishes.
Q2: Is this firmware compatible with other Samsung models?
A: No, this package is strictly for the Samsung Galaxy S21 Ultra 5G SM-G998N using the Samsung Exynos 2100 5G S5E9840 processor. Even a slightly different variant of SM-G998N might use entirely different internal hardware. Installing the wrong file can ruin your phone. Verify your exact model in Settings › About Phone.
Q3: Can I downgrade from the latest version to an older firmware version?
A: While sometimes possible on Exynos processors, I advise against it. Rolling back can create security vulnerabilities and app crashes on Android 11, One UI 3.1. If the newest update is giving you trouble, leave a comment below so we can find a better solution.
Q4: What should I do if I encounter an FRP lock after flashing?
A: Grab our free Android apps launcher. FRP activates on the Samsung Galaxy S21 Ultra 5G SM-G998N when a Google account stays logged in during a flash. Removing the account first is the easiest way to avoid this completely.
Q5: Are custom ROM options available for the Samsung Galaxy S21 Ultra 5G SM-G998N?
A: This article focuses entirely on official stock software. Whether custom ROMs exist for the Samsung Galaxy S21 Ultra 5G SM-G998N depends on open-source kernel support for the Samsung Exynos 2100 5G S5E9840. Visit our Custom ROMs page or the XDA Developers forum to find specific custom builds.
Q6: My Samsung Galaxy S21 Ultra 5G SM-G998N is not detected by Odin. What should I do?
A: Start by reinstalling the Samsung USB drivers and rebooting your computer. Move to a USB 2.0 port instead of USB 3.0, as Samsung phones connect more reliably to the older ports. Temporarily turn off your antivirus. If it still fails, drop a comment with the error message and I will help you troubleshoot.
Q7: How do I enter recovery mode on my Samsung Galaxy S21 Ultra 5G SM-G998N?
A: Turn the phone off entirely, then press Volume Up + Power together until the recovery menu opens. On older Samsung phones with a physical Home button, press Volume Up + Home + Power. The recovery menu displays the build number for your Samsung Galaxy S21 Ultra 5G SM-G998N, which helps verify your current software version.
Q8: My IMEI shows “unknown” after flashing the Samsung Galaxy S21 Ultra 5G SM-G998N. Is my phone permanently damaged?
A: No, your phone is not ruined, even though it looks bad. Read the IMEI repair guide in the troubleshooting section. Samsung phones usually suffer from a wiped EFS partition. Wait to put a SIM card in until the IMEI is fixed.
Q9: How long does it take to flash Samsung Galaxy S21 Ultra 5G SM-G998N firmware?
A: The Odin flashing stage typically lasts 3 to 10 minutes, depending on file size and USB speed. The first reboot takes another 3 to 8 minutes. Leave the phone alone during both stages. If the Odin progress bar freezes, wait a few extra minutes before assuming it failed.
Final Thoughts on Samsung Galaxy S21 Ultra 5G SM-G998N Firmware
That covers the entire process for safely installing the official Samsung Galaxy S21 Ultra 5G SM-G998N firmware (the latest version) with Odin. If you followed the instructions carefully, your phone should boot up cleanly and run smoothly.
If you hit a snag, like an error message or a step that refuses to work, leave a comment below. Tell me exactly what happened, which step you are on, and what you have tried so far. I read the comments and will help you figure it out.
If this walkthrough saved your phone, please share it with someone else who might need the help.
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.
