Samsung Galaxy Watch5 (SM-R900) Firmware Overview
What is the latest SM-R900 firmware?
R900ZCS2DZG3, released August 18, 2026 with Android 16. It is a security update on bootloader binary 2. The archive holds 38 official builds across 19 regions (CSC).
Is the Samsung Galaxy Watch5 still getting updates?
Yes. The newest build is from August 2026, and 19 of 19 regions already have a build from that month; the rest usually follow within a few weeks.
Which Android versions did it get?
The SM-R900 builds in the archive run Android 11 to 16. The earliest build we have for each version:
- Android 16: R900XXU2DZB6 (Mar 2026), 37 builds in total
- Android 11: R900ZCU1AWD6 (May 2023), 1 build in total
Can I downgrade the SM-R900 firmware?
Only to builds with the same bootloader binary (the Bit column) or higher. In the archive the binary of this model rose from 1 to 2:
- Binary 2 — since Feb 2026
- Binary 1 — since Apr 2023
A phone already on binary 2 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 2 build. How to read a build number.
All SM-R900 firmware builds
| Build / PDA | Bit | Region (CSC) | Android | Date | Download Link |
|---|---|---|---|---|---|
|
R900ZCS2DZG3
Security update
|
2 | CHC | 16 |
2026-08-18 | Download |
|
R900XXS2DZG3
Security update
|
2 | XAC | 16 |
2026-08-11 | Download |
|
R900XXS2DZG3
Security update
|
2 | XAA | 16 |
2026-08-11 | Download |
|
R900XXS2DZG3
Security update
|
2 | XJP | 16 |
2026-08-11 | Download |
|
R900XXS2DZG3
Security update
|
2 | TGY | 16 |
2026-08-11 | Download |
|
R900XXS2DZG3
Security update
|
2 | BVO | 16 |
2026-08-11 | Download |
|
R900XXS2DZG3
Security update
|
2 | ARO | 16 |
2026-08-11 | Download |
|
R900XXS2DZG3
Security update
|
2 | KOO | 16 |
2026-08-11 | Download |
|
R900XXS2DZG3
Security update
|
2 | XSG | 16 |
2026-08-11 | Download |
|
R900XXS2DZG3
Security update
|
2 | BRI | 16 |
2026-08-11 | Download |
|
R900XXS2DZG3
Security update
|
2 | BTU | 16 |
2026-08-11 | Download |
|
R900XXS2DZG3
Security update
|
2 | BGL | 16 |
2026-08-11 | Download |
|
R900XXS2DZG3
Security update
|
2 | BNG | 16 |
2026-08-11 | Download |
|
R900XXS2DZG3
Security update
|
2 | AUT | 16 |
2026-08-11 | Download |
|
R900XXS2DZG3
Security update
|
2 | INU | 16 |
2026-08-11 | Download |
|
R900XXS2DZG3
Security update
|
2 | XNZ | 16 |
2026-08-11 | Download |
|
R900XXS2DZG3
Security update
|
2 | ACR | 16 |
2026-08-11 | Download |
|
R900XXS2DZG3
Security update
|
2 | ATO | 16 |
2026-08-11 | Download |
|
R900XXS2DZG3
Security update
|
2 | AFR | 16 |
2026-08-11 | Download |
|
R900ZCS2DZE1
Security update
|
2 | CHC | 16 |
2026-06-22 | Download |
|
R900XXS2DZE1
Security update
|
2 | XAC | 16 |
2026-06-15 | Download |
|
R900XXS2DZE1
Security update
|
2 | INU | 16 |
2026-06-15 | Download |
|
R900XXS2DZE1
Security update
|
2 | KOO | 16 |
2026-06-15 | Download |
|
R900XXS2DZE1
Security update
|
2 | XNZ | 16 |
2026-06-15 | Download |
|
R900XXS2DZE1
Security update
|
2 | BTU | 16 |
2026-06-15 | Download |
|
R900XXS2DZE1
Security update
|
2 | BRI | 16 |
2026-06-15 | Download |
|
R900XXS2DZE1
Security update
|
2 | BNG | 16 |
2026-06-15 | Download |
|
R900XXS2DZE1
Security update
|
2 | BGL | 16 |
2026-06-15 | Download |
|
R900XXS2DZE1
Security update
|
2 | ATO | 16 |
2026-06-15 | Download |
|
R900XXS2DZE1
Security update
|
2 | AUT | 16 |
2026-06-15 | Download |
|
R900XXS2DZE1
Security update
|
2 | ARO | 16 |
2026-06-15 | Download |
|
R900XXS2DZE1
Security update
|
2 | AFR | 16 |
2026-06-15 | Download |
|
R900XXS2DZE1
Security update
|
2 | ACR | 16 |
2026-06-15 | Download |
|
R900XXS2DZE1
Security update
|
2 | BVO | 16 |
2026-06-15 | Download |
|
R900ZCU2DZC1
Feature update
|
2 | CHC | 16 |
2026-03-30 | Download |
|
R900XXU2DZB6
Feature update
|
2 | INU | 16 |
2026-03-10 | Download |
|
R900XXU2DZB6
Feature update
|
2 | XNZ | 16 |
2026-03-10 | Download |
|
R900ZCU1AWD6
Feature update
|
1 | CHC | 11 |
2023-05-17 | Download |
Latest SM-R900 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 |
|---|---|---|---|---|
| ACR | R900XXS2DZG3 | 2 | 16 | 2026-08-11 |
| AFR | R900XXS2DZG3 | 2 | 16 | 2026-08-11 |
| ARO | R900XXS2DZG3 | 2 | 16 | 2026-08-11 |
| ATO | R900XXS2DZG3 | 2 | 16 | 2026-08-11 |
| AUT | R900XXS2DZG3 | 2 | 16 | 2026-08-11 |
| BGL | R900XXS2DZG3 | 2 | 16 | 2026-08-11 |
| BNG | R900XXS2DZG3 | 2 | 16 | 2026-08-11 |
| BRI | R900XXS2DZG3 | 2 | 16 | 2026-08-11 |
| BTU | R900XXS2DZG3 | 2 | 16 | 2026-08-11 |
| BVO | R900XXS2DZG3 | 2 | 16 | 2026-08-11 |
| CHC | R900ZCS2DZG3 | 2 | 16 | 2026-08-18 |
| INU | R900XXS2DZG3 | 2 | 16 | 2026-08-11 |
| KOO | R900XXS2DZG3 | 2 | 16 | 2026-08-11 |
| TGY | R900XXS2DZG3 | 2 | 16 | 2026-08-11 |
| XAA | R900XXS2DZG3 | 2 | 16 | 2026-08-11 |
| XAC | R900XXS2DZG3 | 2 | 16 | 2026-08-11 |
| XJP | R900XXS2DZG3 | 2 | 16 | 2026-08-11 |
| XNZ | R900XXS2DZG3 | 2 | 16 | 2026-08-11 |
| XSG | R900XXS2DZG3 | 2 | 16 | 2026-08-11 |
How to Flash SM-R900 Firmware
Put the Samsung Galaxy Watch5 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 2 or higher if your phone is already on the latest firmware. Use HOME_CSC to keep your data, CSC for a full wipe.