Samsung Galaxy S21 FE 5G (SM-G990U3) Firmware Overview
What is the latest SM-G990U3 firmware?
G990U3UESNIZI2, released October 6, 2026 with Android 16. It is a security update on bootloader binary 23. The archive holds 20 official builds across 18 regions (CSC). Each one is the full stock ROM (flash file) for Odin, not an OTA patch.
Is the Samsung Galaxy S21 FE 5G still getting updates?
Yes. The newest build is from October 2026, and 18 of 18 regions already have a build from that month; the rest usually follow within a few weeks.
Can I downgrade the SM-G990U3 firmware?
Only to builds with the same bootloader binary (the Bit column) or higher. In the archive the binary of this model rose from 22 to 23:
- Binary 23 — since Sep 2026
- Binary 22 — since Aug 2026
A phone already on binary 23 rejects builds with a lower binary in Odin ("SW REV CHECK FAIL"), so it can go back to an earlier Android version only if that version has a binary 23 build. How to read a build number.
All SM-G990U3 firmware builds
| Build / PDA | Bit | Region (CSC) | Android | Date | Download Link |
|---|---|---|---|---|---|
|
G990U3UESNIZI2
Security update
|
23 | ATC | 16 |
2026-10-06 | Download |
|
G990U3UESNIZI2
Security update
|
23 | AIO | 16 |
2026-10-06 | Download |
|
G990U3UESNIZI2
Security update
|
23 | ATT | 16 |
2026-10-06 | Download |
|
G990U3UESNIZI2
Security update
|
23 | CCT | 16 |
2026-10-06 | Download |
|
G990U3UESNIZI2
Security update
|
23 | USC | 16 |
2026-10-06 | Download |
|
G990U3UESNIZI2
Security update
|
23 | ACG | 16 |
2026-10-06 | Download |
|
G990U3UESNIZI2
Security update
|
23 | DSA | 16 |
2026-10-06 | Download |
|
G990U3UESNIZI2
Security update
|
23 | LRA | 16 |
2026-10-06 | Download |
|
G990U3UESNIZI2
Security update
|
23 | CHA | 16 |
2026-10-06 | Download |
|
G990U3UESNIZI2
Security update
|
23 | TMB | 16 |
2026-10-06 | Download |
|
G990U3UESNIZI2
Security update
|
23 | DSH | 16 |
2026-10-06 | Download |
|
G990U3UESNIZI2
Security update
|
23 | VZW | 16 |
2026-10-06 | Download |
|
G990U3UESNIZI2
Security update
|
23 | XAA | 16 |
2026-10-06 | Download |
|
G990U3UESNIZI2
Security update
|
23 | TFN | 16 |
2026-10-06 | Download |
|
G990U3UESNIZI2
Security update
|
23 | TMK | 16 |
2026-10-06 | Download |
|
G990U3UESNIZI2
Security update
|
23 | XAR | 16 |
2026-10-06 | Download |
|
G990U3UESNIZI2
Security update
|
23 | XAG | 16 |
2026-10-06 | Download |
|
G990U3UESNIZI2
Security update
|
23 | FKR | 16 |
2026-10-06 | Download |
|
G990U3UESMIZH2
Security update
|
22 | TFN | 16 |
2026-09-02 | Download |
|
G990U3UESMIZH2
Security update
|
22 | XAR | 16 |
2026-09-02 | Download |
Latest SM-G990U3 Firmware by Region
The newest build for each region (CSC) code. Not sure which region your phone uses? See the CSC code guide.
| Region | Latest build | Bit | Android | Date |
|---|---|---|---|---|
| ACG | G990U3UESNIZI2 | 23 | 16 | 2026-10-06 |
| AIO | G990U3UESNIZI2 | 23 | 16 | 2026-10-06 |
| ATC | G990U3UESNIZI2 | 23 | 16 | 2026-10-06 |
| ATT | G990U3UESNIZI2 | 23 | 16 | 2026-10-06 |
| CCT | G990U3UESNIZI2 | 23 | 16 | 2026-10-06 |
| CHA | G990U3UESNIZI2 | 23 | 16 | 2026-10-06 |
| DSA | G990U3UESNIZI2 | 23 | 16 | 2026-10-06 |
| DSH | G990U3UESNIZI2 | 23 | 16 | 2026-10-06 |
| FKR | G990U3UESNIZI2 | 23 | 16 | 2026-10-06 |
| LRA | G990U3UESNIZI2 | 23 | 16 | 2026-10-06 |
| TFN | G990U3UESNIZI2 | 23 | 16 | 2026-10-06 |
| TMB | G990U3UESNIZI2 | 23 | 16 | 2026-10-06 |
| TMK | G990U3UESNIZI2 | 23 | 16 | 2026-10-06 |
| USC | G990U3UESNIZI2 | 23 | 16 | 2026-10-06 |
| VZW | G990U3UESNIZI2 | 23 | 16 | 2026-10-06 |
| XAA | G990U3UESNIZI2 | 23 | 16 | 2026-10-06 |
| XAG | G990U3UESNIZI2 | 23 | 16 | 2026-10-06 |
| XAR | G990U3UESNIZI2 | 23 | 16 | 2026-10-06 |
How to Flash SM-G990U3 Firmware
Put the Samsung Galaxy S21 FE 5G into Download Mode, load the BL, AP, CP and CSC files into Odin on a Windows PC and press Start. Pick a build with Bit 23 or higher if your phone is already on the latest firmware. Use HOME_CSC to keep your data, CSC for a full wipe.