Since Android is based on the Linux kernel, getting root access to the internal system is just like getting administrator permissions in Windows operating systems. You need those permissions to get the most out of your device. Who looks using Windows without administrator permissions, right? There are some downsides to having root access on your Android phone, however. For starters, with LG phones, you cannot use them under warranty with root access; you must unroot the device first. That’s the most common reason for people choosing to unroot. The other reason is people want to revert back to a stock ROM. The stock ROM is the same ROM (software) your LG G4 comes with out of the box; thus you shouldn’t have any differences. Whatever problems you were facing while having root access — if you were having any problems at all — will not matter once you flash the new stock ROM. It overrides every change you have made before.


The Files You Need

  • Download the International stock ROM for the LG G4 H815 from this page.
  • Download the Flash Tool from this page.
  • The following guide is only made for the International variant of the LG G4. Do not follow this guide on any of the other devices from other phone carrier networks.
  • You must use a Windows PC to follow this guide. All Windows operating systems should work apart from that Windows RT that comes with a Microsoft Surface tablet. Note that not all Surface tablets come with Windows RT. With Windows RT, you are restricted to using the Windows Store Apps.

Unrooting the LG G4 International (H815 model)

  1. Unzip and extract the Flash Tool and the H815 stock ROM to the desktop.
  2. Find out the cellular frequency of your model by visiting this Android central forum.
  3. Long-press the Power button to shut the device off.
  4. Boot it up in download mode. Do that by connecting the USB cable to the computer. Now hold the Volume Up button and connect the other end of the USB cable to the smartphone.
  5. You should now have the G4 in download mode.
  6. Click the ‘Select Type’ drop down box in Flash Tool and choose GSM from the list.
  7. Now look where it says ‘PhoneMode’ and select ‘DIAG’.
  8. Now select your firmware file from the computer you downloaded earlier and upload it where it says ‘Select KDZ File’.
  9. Click the ‘CSE Flash’.
  10. Click the Start button on the following screen.
  11. Click ‘OK’ from the next screen without selecting a country or region.
  12. Now the new stock ROM will flash on your device. The stock ROM will give your device Android Lollipop.
  13. Reboot the device after the firmware file is finished flashing and your device is unrooted.