If your goal is to play games on your phone rather than preparing them for a console, you can use modern Android emulators that often handle large files without splitting:
: Automatically breaks large ISO files (over 4GB) into smaller "ul.*" segments that a FAT32-formatted USB drive can read.
While USBUtil is natively a Windows application (.exe), Android users can run it using a Windows emulator like . Usbutil V2.00 Ps2 For Android
Set the destination to a folder or a connected USB drive (via OTG).
: Install a Windows emulator on your Android device. If your goal is to play games on
: An open-source, beginner-friendly option that doesn't require BIOS files.
: A newer option built from AetherSX2 source code, designed for easy game management. How to Add Large 4GB PS2 Games to FAT32 USB for Free Mcboot : Install a Windows emulator on your Android device
: Widely considered the gold standard for PS2 emulation on Android, offering high performance on Snapdragon-based devices.
: Move the resulting split files and the ul.cfg to the root of your USB drive for use on your PS2 console. Enhancing the Experience with Android PS2 Emulators