Repair Mode can be found in the Battery and Device Care settings. As soon as the mode is activated, the smartphone will reboot.
In this mode, all personal data including photos, messages, accounts and even apps will be hidden (only default apps will be active). In fact, the phone will be like a factory reset. However, if you unlock your smartphone with your fingerprint or pattern, the recovery mode will start. The device will reboot, but this time it will have full access to all data.
Recovery mode will come to Galaxy S21 series smartphones via a software update. Samsung promises to “expand it to some other models in the future”.
Source: Ferra
