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

NOTE: Before you reset 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. Access “Phone Management
  3. Tap “Backup & Reset
  4. Clear or tick the boxes associated with “Automatic Restore” and “Back up my data
  5. Tap “Backup account
  6. Select the desired account
  7. Tap “Factory data reset” and optionally, choose to “Erase SD card” too
  8. If your phone is lock-screen protected, enter your password/PIN and tap “Continue
  9. When ready, tap “delete all” > “Reset

Factory Reset via Recovery:

NOTE: If your phone freezes, crashes, or otherwise prevents you from resetting it via Settings, you can try resetting the device from Android Recovery.

  1. Turn the phone Off
  2. Then press and hold “Power” and “Volume down” at the same time
  3. At the LG screen, release and quickly press “Power
  4. Release the keys at the “Factory data reset’ screen
  5. Press “Volume down” repeatedly to navigate the menu and highlight “Yes
  6. Press “Power” to select the highlight
  7. When prompted to “Erase all user data and restore defaults” prompt, use the “Volume” key to highlight “Yes
  8. Press “Power” to confirm

See More: LG G7 One: Factory Reset via Settings or Android Recovery