Unlocking the bootloader is the first step to unlocking the true potential of your Android smartphone. A bootloader is a small program that places the operating system on to your devices' memory. Some bootloaders, however, contain an extra layer of security that checks to make sure that it only loads an approved version of the operating system. This is the reason OEMs encrypt bootloaders and make it so that users can unlock it only with an unlock code. The practice varies from company to company; while some companies such as Google and OnePlus don't make their users apply for an unlock code, others such as Huawei disallow bootloader unlocking altogether. Today, we'll be taking a look into how to unlock the bootloader on a Google Pixel 4.
How to unlock the bootloader on the Google Pixel 4 and Pixel 4 XL
Before you proceed, you must know that unlocking the bootloader triggers a complete wipe of the device, so its best that you back up your data. Additionally, several banking apps and others such as Google Pay and Pokemon Go might not work properly on a device with an unlocked bootloader. In some rare cases, it may even brick your phone permanently, so proceed with caution. Lastly, you need to have ADB and Fastboot up and running on your computer, so if you don't we'd recommend you get familiar with the process first. Here's a good resource to get started on the process. Now that we have that out of the way, let's get right into it.
Step 1: Enable Developer Options on your Pixel 4. You can do it by following the steps in this post.
Step 2: Navigate to Settings> Developer Options, scroll down a little and find a toggle that says "enable OEM unlocking," and toggle it on.
Step 3: Download ADB and Fastboot and set it up for your PC/Mac. Once downloaded, head over to the download location, and open a command prompt/terminal.
Step 4: Power off your device. While powering it back on, press and hold the Power and Volume Up rocker together to get into the Bootloader menu
Step 5: Connect your phone to your PC/Mac via a USB cable and type:
fastboot flashing unlock
Step 6: Use the volume button to navigate and the power button to accept the on-screen prompt. The process will now begin and your phone will automatically reboot into Android once it is done.
So there you have it, you have now successfully unlocked the bootloader on your Google Pixel 4. You can also re-lock the bootloader at any time, but we recommend that you don't go down that road as it also involves a total wipe of the device. You can now flash a custom recovery such as TWRP and root your phone. Watch this space for guides about how to do that.