Samsung has begun rolling out One UI 8 for the Galaxy S21 FE in Thailand and Vietnam, marking it as the last major Android OS upgrade for the device. This update coincides with the end of its four-year update guarantee. The Galaxy S21 FE will continue to receive monthly security patches for over a year. One UI 8 is built on Android 16 and introduces additional features and enhanced Galaxy AI capabilities. The update is approximately 2GB in size and has the version number G990EXXUIHYJ2. The rollout started on October 23, with no specific timeline for other regions. Samsung's upcoming Galaxy S25 FE is expected to offer a seven-year update promise.