The OnePlus 3 is a great new smartphone, but you will not get far with any customizing of the Android operating system that is running on it without first unlocking the bootloader. The bootloader is what runs the operating system it is will decide how your OnePlus 3 smartphone thinks. By altering the way, the bootloader thinks we can get it to accept things like custom recovery partitions, and that opens other doors like giving us the chance to flash SuperSU and rooting the smartphone.

Here is everything you need to unlock the bootloader on the OnePlus 3 smartphone by using the ADB and Fastboot from a Windows computer and command prompt:

REQUIREMENTS

• The following guide is made for the OnePlus 3 smartphone and will not necessarily unlock the bootloader for any other device in the OnePlus range in the future.
• You will need to have a computer that is running a version of the Windows operating system to use this guide to unlock the OnePlus 3 smartphone.

BEFORE WE BEGIN

• Unlock the Developer Options menu on the OnePlus 3 smartphone by tapping on the Menu > Settings > About Device > Build Number 7 times. After the seventh tap, you should see a message on the display that says you are using the OnePlus handset as a developer which ultimately means that you now have the Developer Options menu available.
• Now it is time to enter the Developer Options that you just unlocked: tap on the Menu > Settings > Developer Options and then check the box that is next to the words ‘USB Debugging.’
• Download and install the universal Windows ADB Drivers on the computer before you start with the installation of the ADB on the Windows computer so your device can get connected to ADB without any issues.

HOW TO UNLOCK BOOTLOADER ON ONEPLUS 3 SMARTPHONES

1. Start by turning off the OnePlus 3 smartphone and reboot it directly into the Fastboot mode by holding the Volume Up and Power buttons simultaneously.
2. Connect the OnePlus 3 smartphone to the computer by using the USB cable that comes with the device out of the box and the same one that you would usually use to charge the OnePlus’s battery.
3. Download and install ADB on your Windows computer and then come directly back to this guide when you have that set up correctly so you can continue with this tutorial.
4. Open the Fastboot folder on the computer and hold down shift while right-clicking the white background within the folder to bring up a new menu on the screen.
5. Choose to open a new command prompt window here from the menu you see on the computer screen.
6. Type the following command in the command prompt window: “fastboot devices” to check whether or not you have Fastboot correctly working on the computer and it manages to detect your device okay.
7. Type the next command into the same command prompt window: “fastboot oem unlock” to start the first phase of the unlocking process on the OnePlus smartphone.
8. Do not touch any buttons on the OnePlus 3 handset while it does its thing; just wait for the bootloader to get unlocked.
9. Type the final command into the command prompt window: “fasboot reboot” to get the OnePlus 3 smartphone rebooting back into the normal mode.

In conclusion, you have now unlocked the OnePlus 3 bootloader, and you are ready to take the things to another level and find out what is required to install a custom recovery on the OnePlus 3 smartphone. The custom recovery partition is going to be your key to immediate NANDroid Backups with the use of applications, as well as playing a vital role in giving your handset root access to the root file system if you would like to head in that direction next.