Samsung Galaxy S24 (SM-S921N) Firmware Overview
What is the latest SM-S921N firmware?
S921NKSSIEZJ1, released October 13, 2026 with Android 17. It is a security update on bootloader binary 18. The archive holds 24 official builds across 4 regions (CSC). Each one is the full stock ROM (flash file) for Odin, not an OTA patch.
Is the Samsung Galaxy S24 still getting updates?
Yes. The newest build is from October 2026, and 4 of 4 regions already have a build from that month; the rest usually follow within a few weeks.
Which Android versions did it get?
The SM-S921N builds in the archive run Android 16 to 17. The earliest build we have for each version:
- Android 17: S921NKSUHEZIF (Sep 2026), 8 builds in total
- Android 16: S921NKSSFDZE1 (May 2026), 16 builds in total
Can I downgrade the SM-S921N firmware?
Only to builds with the same bootloader binary (the Bit column) or higher. In the archive the binary of this model rose from 15 to 18:
- Binary 18 — since Oct 2026
- Binary 17 — since Aug 2026
- Binary 16 — since Jul 2026
- Binary 15 — since May 2026
A phone already on binary 18 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 18 build. How to read a build number.
All SM-S921N firmware builds
| Build / PDA | Bit | Region (CSC) | Android | Date | Download Link |
|---|---|---|---|---|---|
|
S921NKSSIEZJ1
Security update
|
18 | KTC | 17 |
2026-10-13 | Download |
|
S921NKSSIEZJ1
Security update
|
18 | SKC | 17 |
2026-10-13 | Download |
|
S921NKSSIEZJ1
Security update
|
18 | LUC | 17 |
2026-10-13 | Download |
|
S921NKSSIEZJ1
Security update
|
18 | KOO | 17 |
2026-10-13 | Download |
|
S921NKSUHEZIF
Feature update
|
17 | SKC | 17 |
2026-09-21 | Download |
|
S921NKSUHEZIF
Feature update
|
17 | KOO | 17 |
2026-09-21 | Download |
|
S921NKSUHEZIF
Feature update
|
17 | KTC | 17 |
2026-09-21 | Download |
|
S921NKSUHEZIF
Feature update
|
17 | LUC | 17 |
2026-09-21 | Download |
|
S921NKSSHDZH3
Security update
|
17 | SKC | 16 |
2026-08-14 | Download |
|
S921NKSSHDZH3
Security update
|
17 | LUC | 16 |
2026-08-14 | Download |
|
S921NKSSHDZH3
Security update
|
17 | KTC | 16 |
2026-08-14 | Download |
|
S921NKSSHDZH3
Security update
|
17 | KOO | 16 |
2026-08-14 | Download |
|
S921NKSSGDZG1
Security update
|
16 | SKC | 16 |
2026-07-03 | Download |
|
S921NKSSGDZG1
Security update
|
16 | KOO | 16 |
2026-07-03 | Download |
|
S921NKSSGDZG1
Security update
|
16 | KTC | 16 |
2026-07-03 | Download |
|
S921NKSSGDZG1
Security update
|
16 | LUC | 16 |
2026-07-03 | Download |
|
S921NKSSFDZF3
Security update
|
15 | SKC | 16 |
2026-06-09 | Download |
|
S921NKSSFDZF3
Security update
|
15 | LUC | 16 |
2026-06-09 | Download |
|
S921NKSSFDZF3
Security update
|
15 | KTC | 16 |
2026-06-09 | Download |
|
S921NKSSFDZF3
Security update
|
15 | KOO | 16 |
2026-06-09 | Download |
|
S921NKSSFDZE1
Security update
|
15 | KTC | 16 |
2026-05-18 | Download |
|
S921NKSSFDZE1
Security update
|
15 | KOO | 16 |
2026-05-18 | Download |
|
S921NKSSFDZE1
Security update
|
15 | LUC | 16 |
2026-05-18 | Download |
|
S921NKSSFDZE1
Security update
|
15 | SKC | 16 |
2026-05-18 | Download |
Latest SM-S921N 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 |
|---|---|---|---|---|
| KOO | S921NKSSIEZJ1 | 18 | 17 | 2026-10-13 |
| KTC | S921NKSSIEZJ1 | 18 | 17 | 2026-10-13 |
| LUC | S921NKSSIEZJ1 | 18 | 17 | 2026-10-13 |
| SKC | S921NKSSIEZJ1 | 18 | 17 | 2026-10-13 |
How to Flash SM-S921N Firmware
Put the Samsung Galaxy S24 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 18 or higher if your phone is already on the latest firmware. Use HOME_CSC to keep your data, CSC for a full wipe.