WARNING! When you factory reset your phone, all personal data located on the phone’s internal memory will be deleted. This includes media files, ringtones, downloaded content, applications, contacts etc. Furthermore, all settings will be restored to factory values.

NOTE: Before your set your phone, you can visit this thread for a guide on how to back up data, and this thread for a guide on restoring data.

Factory Reset via Settings:

  1. Open the apps drawer
  2. Launch “Settings
  3. Scroll to “Personal” and tap “Backup and reset
  4. Optionally, enable “Back up my data” and “Restore
  5. Tap “Factory data reset
  6. Tap “Reset device
  7. In case your device is protected by a lock screen, enter the PIN / password / pattern to proceed
  8. Tap “Continue” > “Delete all

Factory Reset via Recovery:

NOTE: If your phone freezes, crashes, or otherwise prevents you from resetting it via Settings, alternatively you can try resetting the phone from the Android Recovery menu, which can be accessed by performing a combination of button presses.

  1. Turn off the phone if necessary
  2. Press and hold “Power”, “Volume Up” and “Home” at the same time
  3. At the “Samsung” logo, release “Power
  4. When the “Android” screen appears, release “Home” and “Volume down” too
  5. In the “Android system recovery” menu, press “Volume down” repeatedly to navigate to and highlight “Wipe data / factory reset
  6. Press “Power” to select the highlighted option
  7. Press “Volume down” to highlight “Yes – delete all user data” and press “Power

Check for OS Updates:

NOTE: After you factory reset your device, it’s recommended to verify if new software updates are available for download.

  1. Tap “Apps” on the home screen
  2. Open “Settings
  3. Scroll to “System” and tap “About device
  4. Check if a new update is available. If applicable, follow the on-screen steps to download and apply the update. NOTE: the update process will require at least one reboot. Save any unsaved work before proceeding

See More: Samsung Galaxy A3 (2017): Factory Reset and Check For OS Updates