WARNING! When you master reset your phone, all data stored on the internal memory will be removed, including contacts, apps, downloaded content, media files etc. Furthermore, all settings will be restored to factory values.

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

Factory Reset via Settings:

  1. Tap “Apps” on the home screen
  2. Open “Settings”
  3. If necessary, tap “Menu” and switch to “List view”
  4. Scroll to “Personal” and tap “Backup & reset”
  5. Select or clear the boxes next to “Back up my data” and “Automatic restore”
  6. Tap “Backup account” and follow the on-screen instructions to create or add a Google account
  7. Tap “Factory data reset”
  8. Optionally, enable or disable “Erase SD card”
  9. Tap “Reset phone” > “Next”
  10. Tap “Delete all” > “OK” to confirm

Factory Reset via Recovery:

NOTE: In case you are unable to reset the phone via Settings using the method above, you can try resetting it from Recovery instead. To access the recovery menu, you need to perform a combination of button presses:

  1. Turn off the phone
  2. Press and hold “Power” and “Volume Down” at the same time
  3. At the “LG” logo, release and quickly re-hold “Power”
  4. At the “Factory data reset” prompt, use “Volume Down” to highlight “Yes”
  5. Press “Power” to select the highlighted option
  6. When prompted to “Erase all user data and restore default settings”, press “Volume down” to highlight “Yes”
  7. Press “Power” to select the highlighted option
  8. Wait for your device to reset, and reboot

Check for OS Updates:

NOTE: After a fresh factory reset, you should check if newer software updates are available on the phone. To do so:

  1. Open the apps drawer
  2. Go to “Settings”
  3. Tap “Menu” > “Switch to list view” if necessary
  4. Tap “About phone”
  5. Check for updates and if available, follow the on-screen prompts to download and apply it / them

See More: LG G4c: Factory Reset via Settings or Recovery; Check for OS Updates