LG K51 root, bootloader unlock, twrp & custom ROM lmk500

In the earlier days of Android, rooting was a one-click process without the need for a computer. Until Android lollipop, I rooted my LG phones in a single click using the king root app.  I was able to root the phone even with a locked bootloader. I rooted my LG Tribute 2 in the same manner.

Later on, the root worked only on those devices with an unlockable bootloader. I rooted my LG K20 Plus after unlocking the bootloader.

In this rooting process, we need to

  • enable USB debugging
  • boot into fastboot mode for bootloader unlocking
  • install TWRP
  • flash a Magisk or SuperSU root file via TWRP

Let’s try to follow the same procedure for LG K51 –

How to Root LG K51 LMK500 Boost Mobile, MetroPCS, T-Mobile

Root LG K51 lmk500

There are 2 kinds of rooting apps at present. Magisk is a systemless root. It can be enabled/disabled as per the requirement. Supersu by Chainfire is an age-old but popular rooting app.

To root our K51, let’s enable USB Debugging as follows –


how to root lg k51 lmk500 boost mobile

To enable USB debugging, we need to go to the Developer Options page.

Let’s open Settings > System > Developer Options.


lg k51 rooting

We need to toggle on “USB Debugging”.


LG K51 Developer Options – How to enable

lg k51 root 2020

I’ve accepted the “Allow USB debugging” request by hitting “OK”.

lg lmk500mm root

Now, we are ready to connect our phone to the computer for USB debugging.


lg k51 metro root

The LGE Mobile ADB Interface driver is installed on my PC.

LG K51 USB Driver Download

lg k51 boost mobile root

In the next step, I’m going to launch the “Minimal ADB & Fastboot” tool. Using this tool we can write the ADB command to enter fastboot mode.

lg k51 one click root no pc

We need to check whether the device is ready for USB debugging or not.

The command line adb devices shows our connected phone LMK500 but as unauthorized.

how to root lg k51 lmk500

We need to authorize the connected computer by accepting the “Allow USB debugging” request received on the phone.

root my lg k51

Now, the device LMK500 is ready for USB debugging.

LG K51 Bootloader Unlock


lg k51 bootloader unlock

The ADB command to boot into the fastboot mode is adb reboot bootloader

Let’s try to enter this command line and tap enter on the computer keyboard.


lg k51 unlock bootloader

This command simply reboots the phone. I tried this several times but to no avail.

I made a video on this as well. You can check the below video –

On LG K51, we don’t have access to the fastboot mode.

Without entering the fastboot mode, we cannot write adb command for bootloader unlocking.

lg k51 fastboot mode

The above screen belongs to LG K30 Fastboot mode.

The bootloader unlock command is fastboot oem unlock / fastboot oem device-id

We don’t have access to this fastboot mode on K51.

As of now, there is no way to unlock the LG K51 bootloader. We cannot root our device without unlocking the bootloader.

LG K51 TWRP – Custom Recovery

lg k51 twrp custom recovery

The above TWRP screen shows up after flashing the recovery.img file. The custom recovery can be flashed by writing the adb command fastboot flash recovery recovery.img

As we failed to unlock the K51 bootloader, there is no way to flash the TWRP custom recovery file.

The magisk or supersu root file can be flashed only after installing TWRP on LG K51.

LG K51 Custom ROM – LineagOS

lg k51 lineageos custom rom

A custom ROM such as Lineage OS comes in the form of a flashable zip file. A custom ROM can only be flashed via custom recovery such as TWRP.

As we failed to flash TWRP on LG K51, there is no way to install the LineageOS custom ROM on K51, as of now.

Let’s hope someday LG makes the K51 bootloader unlockable. Only after unlocking the bootloader, we will able to root our device.

If someone claims he can root your LG K51, he is fooling you. There is no way to root the K51 at present.


For any queries or feedback, please leave a comment below. Thanks for reading.



10 thoughts on “LG K51 root, bootloader unlock, twrp & custom ROM lmk500

  1. I have gotten into fastboot on my LG k51. It’s showing fastbootd instead of just fastboot. I tried to run the command that you ran for the LG k30 and in response it says FAILED (remote: unable to open fastboot HAL)

    • Hey Waylon, can you email me an instruction set on exactly how you manage to reach fastbootd? I’d love to take a look around it and see what I can tweak with!

      • I figured out how, you just enable usb debugging in android and type adb reboot fastboot

        And voila, your in fastboot

  2. got to gimme what i figure as a uuid from fastboot interaction but its not like its says lg web site you’ll need read help simply by typling command and figured what read something to like help after but its lg developer page unit say output ewual two hex dec stings needin yo butt together nit likes command nog remote HAL like tiny u
    Linux distro. but after playi g with a few distro of fast adb for win a long hex de
    c uuid as token- identifyR was my device name as opo see d ti original unit

  3. anyone able to unlock the bootloader ?
    I am able to go in the fastboot with the command : adb reboot fastboot
    But how to unlock the bootloader and how to proceed for rooting the LG K51 ?

    • LG website has a page dedicated to unlocking your bootloader, voids your waranty, you will need IMEI number of phone , enter it and they will give you a string of numbers printed out, enter it on same page while LG K51 is plugged in and you should be unlocked.

  4. Hi. I have a hacker who I used Bluetooth. To hack my k51. Installed ROM workgroups now has control of my phones. Now the phone infects other phones tvs wifi ect . no mater what I do.

    • Same here feel like a whole team jumped on my phone and Wi-Fi need blue tooth keyboard not wanting to bring more devices into this hell

  5. Yes hallo how are you doing today, I am the proud owner of a LG K 51, yes you can get into both download and fastboot mode, if you send me a email address, I show proof and general, easy to follow instructions, in short, ADB terminal, have usb_ android inf. Injected, VCOM drivers property installed, LG phone drivers downloaded onto P.C, install platform tools in C:/, open folder, right click and shift inside open folder brings down drop-down menu, open CMD, plug phone into PC, have debugging USB enabled, go to command prompt, type adb devices enter, shows serial number and device, good, now type adb reboot bootloader enter. Your LG K51 will now boot itself into fastboot mode , see, it can be done. You can also hold vol up and power when you plug in USB cord but I forgot exact way, although I have done it many times while learning how to flash my K 51, I hope this helps you and all who read this.

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