While installing a custom recovery image like Team Win’s TWRP on the HTC One M8 allows you to flash files that include kernels, ROMs, and rooting tools, it is the root access that makes it possible to install more apps. These apps can often be available from the Google Play Store, and there are a few good names available from outside the Google Play Store too.
The following guide demonstrates everything you need to root the HTC One M8 smartphone so you can install any of the apps that require access to the root file system before they can run:
- You need to install a custom recovery image on the HTC One M8 smartphone  before you can follow this guide that roots the HTC One M8 smartphone. We are using the custom recovery to flash Chainfire’s SuperSU and SuperSU is not enabled correctly without a modified recovery or custom recovery image installed before the flashing.
BEFORE WE BEGIN
- We recommend you backup the data on the M8 smartphone before rooting it using this guide. You can use the custom recovery partition when it is booted up during the guide to take an NANDroid Backup from the recovery menu. The NANDroid Backup is an excellent way to make a full backup without having to use ADB commands. Once you have completed the guide, you can then install the NANDroid Manager app which is the perfect compliment to the NANDroid Backup. Another popular way to take backups after rooting is by installing the Titanium Backup app from Google Play.
HOW TO ROOT HTC ONE M8 RUNNING ON ANDROID 6.0
- Download the SuperSU 2.76  from Chainfire directly to the computer.
- Connect the HTC One M8 smartphone to the computer with the USB cable.
- Open the Downloads folder on the computer (if using Windows or else open the default download location for your OS) and copy the SuperSU zip file to the internal SD card storage folder for the HTC One M8 smartphone.
- Unplug the One M8 smartphone from the computer once you know the zip file is now on the SD card.
- Turn off the M8 smartphone and reboot it into the recovery mode by holding down the hardware button combination made for the stock recovery and it boots up the custom recovery.
- Take the NANDroid Backup from the menu if you have not made a backup by tapping on the Backup button.
- Tap on the Install button from the main recovery menu and then select the SuperSU zip file from the SD card storage.
- Follow the rest of the guidelines that are on the screen from the custom recovery to complete the installation of the SuperSU.
- Choose the Reboot option, followed by the System option from the recovery menu after the SuperSU is flashed and then it boots back into the normal mode.
In conclusion, that is how to root HTC One M8 smartphones when they are running on the Android 6.0 Marshmallow software updates by flashing Chainfire’s version of the SuperSU which also happens to be systemless. The systemless root version of the SuperSU is used for all rooting guides based on Android 6.0 Marshmallow, and it is known as the cleaner of the two rooting methods which can only be a good thing for your device. It also means that you can unroot just by taking a hard reset from the recovery mode.