How to completely delete all the contents of Samsung mobile phone?

Restoring the factory settings of the mobile phone will erase all data in the internal storage devices of the mobile phone, including SMS, contacts, downloaded applications, etc. Therefore, before restoring the factory settings of the mobile phone, please back up the useful data in the mobile phone to avoid losing it. To restore the factory settings, please follow the following steps:

1. Under the standby page, click Application.

2. Click Settings.

3. Select Reset.

4. Click to restore the factory settings.

5. Click Reset Device.

6. Click Delete All.

After the restart, the phone successfully restored the factory settings.