G998USQSHHYI1 – Galaxy S21 Ultra 5G firmware
Build G998USQSHHYI1 is a security update for the Galaxy S21 Ultra 5G (SM-G998U)
on Android 15 (One UI 7). It first appeared on Samsung's servers on Sep 24, 2025 (method) and has reached
6 regions so far. It raises the bootloader bit from 16 to 17: once installed, the device no longer accepts firmware with bit 16 or lower, so a downgrade to G998USQSGHYF2 is blocked. Samsung still serves this file.
- Model
- SM-G998U
- Android
- Android 15
- Type
- Security
- Bootloader bit
- 17
- First released
- Sep 24, 2025
- Regions
- 6
Rollout timeline by region
The date each region code (CSC) first received G998USQSHHYI1, counted from the first release.
| CSC | Region | Released | Rollout | Version (PDA/CSC/MODEM) |
|---|---|---|---|---|
ATT | USA (AT&T) | Sep 24, 2025 | day 0 | G998USQSHHYI1/G998UOYNHHYI1/G998USQSHHYI1 |
CCT | USA (Comcast) | Sep 28, 2025 | +4 days | G998USQSHHYI1/G998UOYNHHYI1/G998USQSHHYI1 |
SPR | USA (Sprint) | Sep 28, 2025 | +4 days | G998USQSHHYI1/G998UOYNHHYI1/G998USQSHHYI1 |
TMB | USA (T-Mobile) | Sep 28, 2025 | +4 days | G998USQSHHYI1/G998UOYNHHYI1/G998USQSHHYI1 |
VZW | USA (Verizon) | Sep 29, 2025 | +5 days | G998USQSHHYI1/G998UOYNHHYI1/G998USQSHHYI1 |
USC | USA (US Cellular) | Oct 6, 2025 | +12 days | G998USQSHHYI1/G998UOYNHHYI1/G998USQSHHYI1 |
Download and release notes
samloader download -m SM-G998U -r ATT -v G998USQSHHYI1/G998UOYNHHYI1/G998USQSHHYI1Samsung's release notes and security patch level for this update: SM-G998U / ATT on doc.samsungmobile.com. What each part of the build number means: decode G998USQSHHYI1.