WARNING! By factory resetting your phone, all your personal data stored on the phone’s internal memory will be deleted, including media files, ringtones, contacts, downloaded content etc. Furthermore, all settings will be restored to factory values, but data located on the SIM and SD cards won’t be affected.

NOTE: Before resetting the phone, you can check this thread for a guide on how to back up data, and this thread for instructions on restoring data.

Factory Reset via Settings:

  1. Open “Settings
  2. Go to “Phone Management
  3. Tap “Backup & Reset
  4. Tick or clear the check boxes associated with “Back up my data” and “Automatic Restore
  5. Tap “Backup account” and select the desired account
  6. Tap “Factory data reset” and optionally, select whether or not to “Erase SD Card
  7. If your phone is protected by a lock screen, enter your password/PIN to proceed
  8. Tap “Continue” > “Delete all
  9. Tap “Reset” when ready

Factory Reset via Android Recovery:

NOTE: If your phone crashes, freezes, or otherwise prevents you from resetting it via settings, alternatively you can try resetting the phone using hardware keys via Android Recovery.

  1. Turn the phone Off
  2. Press and hold “Volume down” and “Power” simultaneously
  3. At the LG screen, release and quickly press “Power
  4. At the “Factory data reset” screen release the buttons
  5. In Recovery, press “Volume down” repeatedly to navigate the menu and highlight “Yes
  6. Press “Power” to select the highlighted option
  7. At the “Erase all user data and restore defaults” prompt, highlight “Yes” and press “Power

See More: LG V40 ThinQ: Factory Reset via Settings or Android Recovery