Androidtalk.us If you want to keep your device always updated with an official firmware the only thing you have to do is to follow with caution my next tutorial. androidtalk.us recommends you to install official firmware instead of a Custom Rom because is more stable and the battery life is greater. An official firmware is made exclusively for that type of device, in our case Samsung Galaxy S3. Another great think is that you don’t have to Root your device in order to install an official firmware. You don’t have to backup your data because you won’t lose anything after flashing a new official firmware using this method.