Samsung Galaxy Watch4 (SM-R865U) Firmware Overview
What is the latest SM-R865U firmware?
R865USQS2JZG3, released August 21, 2026 with Android 16. It is a security update on bootloader binary 2. The archive holds 13 official builds across 1 region (CSC).
Is the Samsung Galaxy Watch4 still getting updates?
Yes. The newest build is from August 2026.
Which Android versions did it get?
The SM-R865U builds in the archive run Android 11 to 16. The earliest build we have for each version:
- Android 16: R865USQU1JYL6 (Feb 2026), 3 builds in total
- Android 14: R865USQU1IXK1 (Feb 2025), 4 builds in total
- Android 13: R865USQU1HWL1 (Dec 2023), 2 builds in total
- Android 11: R865USQU1DUJC (Nov 2021), 3 builds in total
Can I downgrade the SM-R865U 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 Oct 2021
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-R865U firmware builds
| Build / PDA | Bit | Region (CSC) | Android | Date | Download Link |
|---|---|---|---|---|---|
|
R865USQS2JZG3
Security update
|
2 | XAA | 16 |
2026-08-21 | Download |
|
R865USQS2JZE1
Security update
|
2 | XAA | 16 |
2026-06-23 | Download |
|
R865USQU1JYL6
Feature update
|
1 | XAA | 16 |
2026-02-04 | Download |
|
R865USQU1IYI1
Feature update
|
1 | XAA | 14 |
2025-10-23 | Download |
|
R865USQS1IYE1
Security update
|
1 | XAA | 14 |
2025-07-11 | Download |
|
R865USQU1IYCD
Feature update
|
1 | XAA | 14 |
2025-06-18 | Download |
|
R865USQU1IXK1
Feature update
|
1 | XAA | 14 |
2025-02-14 | Download |
|
R865USQU1HXB7
Feature update
|
1 | XAA | 13 |
2024-03-26 | Download |
|
R865USQU1HWL1
Feature update
|
1 | XAA | 13 |
2023-12-28 | Download |
|
R865USQU1GWDA
Feature update
|
1 | XAA | 11 |
2023-05-18 | Download |
|
R865USQU1GWB2
Feature update
|
1 | XAA | 11 |
2023-02-27 | Download |
|
R865USQU1DUJC
Feature update
|
1 | XAA | 11 |
2021-11-15 | Download |
|
R865USQU2JZB6
Feature update
|
2 | XAA | — |
N/A | Download |
How to Flash SM-R865U Firmware
Put the Samsung Galaxy Watch4 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.