Samsung Galaxy Watch4 40mm LTE (SM-R865F) firmware for Japan (AU KDDI) (KDI): 2 builds in the SamMobile archive, newest first. The latest is R865FXXS2JZE1 (Android 16, built 21 May 2026). Open a build to download it, or switch region with the country selector.
We recommend using Samsung’s own utilities, Samsung Smart Switch and OTA (Over-the-air), to upgrade devices. Use SamMobile only if you are 100% sure about the risks involved in flashing
your device. SamMobile is not responsible for any damage caused by using the files on this website.