Samsung Galaxy S24 (SM-S921U1) - FKR - S921U1UEU4BYCH firmware
Samsung Galaxy S24 firmware S921U1UEU4BYCH is the Android 15 build for the Samsung Galaxy S24 (model SM-S921U1), released by Samsung for USA (FKR). It was built on 29 March 2025, carries the 2025-04-01 Android security patch, has changelist 30959686. The package combines system build S921U1UEU4BYCH (AP/PDA) with CSC build S921U1OYM4BYCH for the FKR region code. The download is 11.9 GB and has MD5 checksum 0e521a7b6d468f4edd6a365c80a1278a, so you can verify the file after downloading. SamMobile added this file to the firmware archive on 9 April 2025.
How to flash S921U1UEU4BYCH on the Samsung Galaxy S24 (SM-S921U1)
We recommend updating through Samsung's own tools: over-the-air (Settings › Software update) or Samsung Smart Switch on a PC. Flash the full firmware with Odin only when you are sure about the risks. A wrong region or a failed flash can brick the device, and SamMobile is not responsible for any damage.
- Download the firmware package above and extract the ZIP. It contains the AP (PDA), BL, CP and CSC files, plus a HOME_CSC file.
- Download and extract Odin on a Windows PC, and install the Samsung USB drivers if the PC does not detect the phone.
- Switch the device off and boot it into Download mode (usually Volume Up + Volume Down while connecting the USB cable, or Volume Down + Bixby + Power on older models).
- Open Odin. The ID:COM box turns blue when the device is connected.
- Load the files in their slots: BL, AP, CP and CSC. Use HOME_CSC to keep your apps and data, CSC to wipe the device.
- Leave Re-Partition unticked and click Start. The device reboots when Odin shows PASS. The first boot after a flash can take a few minutes.
Step-by-step PDFs: 5-file firmware and 1-file firmware.
What the build numbers mean
PDA / AP (S921U1UEU4BYCH) is the Android system build; its last three characters encode the year, month and revision. CSC (S921U1OYM4BYCH) is the region and carrier configuration, and CP is the modem firmware. The product code FKR identifies the region or carrier this package was made for (USA); our list of Samsung CSC codes maps every code to its country and carrier. Flashing a package for a different product code changes carrier features and can be refused by the bootloader, so pick the one that matches the CSC shown under Settings › About phone › Software information.