A KDZ file is the official stock ROM format used by LG. It is a compressed package containing the entire operating system, bootloader, modem settings, and system apps. Unlike custom ROMs, KDZ files are digitally signed by LG, making them the safest way to restore a phone to its factory state without voiding most warranties or risking permanent damage. Why You Might Need a New KDZ File
Before updating your LG phone using a KDZ firmware file, make sure to: kdz firmware file for lg phone new