Like any Android device, the LG G3 smartphone can be rooted and there are two ways to do it - via IO Root or thru Root Tool. Both rooting kits are applicable to several models including the international and the United States variants.
Before performing the rooting procedure, fulfil the following requirements below for LG G3.
1. Create a manual backup of all data files and personal settings on the smartphone.
2. Check if the battery level is at least 50 per cent to avoid power interruption.
3. Enable USB debugging mode by going to Settings > Tap About Phone five to ten times > Go back > Developer Options > Enable USB Debugging Mode.
4. If you can access the Recovery Mode, perform a nAndroid backup to create a copy of the current ROM running on the device.
Warning: We are not responsible for any errors which may occur on your LG G3. Rooting the device will remove any active warranty. Do this at your own risk.
Gaining Root Access
Using IO Rooting Kit (untethered):
1. IO Root supports the following LG G3 variant and respective firmware version:
a. Korean F400K/L/S Android 4.4.2 10A/10B.
b. Sprint LS990 Android 4.4.2 ZV2.
c. International D855 Android 4.4.2 XXX.
2. Download the IO Root Tool on the computer then extract its files to a location easy to access.
3. Turn on the Airplane Mode on the LG G3 to avoid interruptions from SMS or any other wireless connectivity.
4. Connect the smartphone to the computer using a USB cable.
5. Open the IO Root folder on the computer then launch the "root.bat" file.
6. Press Enter key once the Command Window appears. It will reboot the smartphone.
7. After the installation, the device will reboot and may take three to five minutes before reaching the home screen.
Using Root Tool:
1. Root Tool supports the following models of LG G3 smartphone:
a. Korean F400K/L/S
b. International D855
c. AT&T D850
d. T-Mobile D851
e. Canadian LG-D852
f. Sprint LS990
g. Verizon VS985
2. Download the Root Tool zip on the computer.
3. Extract the Root Tool to a location easy to access.
4. Connect the LG G3 to the computer using a USB cable.
5. Open the Root Tool folder then launch the "run.bat" file.
6. Follow the screen instructions on the computer and on the device.
7. Once the Recovery screen appears, select "update from ADB" option by pressing the volume keys for navigation and power key to confirm.
8. After the zip file has been installed, select "reboot system now." LG G3 will restart and may take three to five minutes before reaching the home screen.
In order to check if the device has been successfully rooted, download the Root Check app from the Google Play Store. If you have any errors in using IO Root, send your feedback to its official XDA forum page.