The OnePlus 6 comes with Android 8.1 Oreo which is currently the latest stable Android version. OnePlus has always kept a minimalistic approach to the UI of its phones. The OnePlus 6 comes with OxygenOS ROM, which is a slightly modified version of stock vanilla Android. For most, OxygenOS is more than enough. However, some people do not want the stock experience and want to install custom ROMs and other files to their phones.
In order to flash files on the OnePlus 6, the bootloader needs to be unlocked. All OnePlus 6 devices come with a locked bootloader, which prevents users from flashing and installing files. The bootloader is an important part of every Android phone. It is the gateway to root access. With a locked bootloader you cannot root your phone or install a custom ROM. If you want to do any of these things, then you have to unlock the bootloader on your OnePlus 6.
How To Unlock Locked OnePlus 6 Bootloader
Note: Before you begin unlocking the bootloader of your phone, please note that doing so will wipe everything on your phone. Before you do anything, make a full backup of all files and important files.
You also need proper USB and Fastboot drivers, so your computer can properly communicate with your phone.
1. Download and install OnePlus 6 USB drivers here.
2. Connect your phone to your computer using a USB cable.
3. Open Command Prompt on your computer. To do so, press Shift + Right Click and a menu will appear. Click on “Open Command Window here”.
4. Type “fastboot devices” and press enter. If you have installed the drivers correctly, the computer will display your phone’s serial number.
5. Now, type “fastboot oem unlock” and press enter. This will wipe everything on your phone and will unlock the bootloader.
6. Once you press enter, a warning page will show up. Select “Yes” and press the power button to execute it.
The bootloader will now be unlocked. The phone will restart and then you will be able to root it, install custom ROMs and much more.