How to Unlock the Bootloader on Samsung Galaxy Phones [Guide]
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. Samsung, much like Google and OnePlus, makes it easy for users to unlock the device's bootloader
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, some apps don't play nice with an unlocked bootloader. If the process is interrupted for whatever reason, you run the risk of bricking your device. Taking it to a service center won't be of much help either, as it voids the warranty. 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.
IMPORTANT: Read this part carefully before unlocking the bootloader on your Samsung Galaxy Phone
Before you proceed, do note that unlocking the bootloader will trigger Knox once and for all. You'll never be able to use services such as Samsung Pay and Secure Folder. What's worse is that any data you have in the Secure Folder will be unrecoverable. Re-locking the bootloader will not undo the change as it is a one-time process. you can read more about it here.
Now that we have that out of the way, let's get right into it.
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 with administrator privileges.
Step 4: Ensure that the phone is detected by your PC/Mac by typing in the following command.
Step 5: Once you get a confirmation that your device has been detected, type the following command
adb reboot bootloader
Step 7: Your phone should reboot into the bootloader shortly after. If it doesn't you can manually boot your phone into the bootloader by powering off the device and pressing and holding the Power and Volume Up rocker together when powering it back on.
Step 8: Now that your phone is in the bootloader mode, type the following command:
fastboot flashing unlock
Step 9: Use the volume button to navigate and the power button to accept the on-screen prompt. WARNING: This step will delete all data on your phone. Wait for the process to complete and then type:
Step 10: Your phone should now reboot into Android with an unlocked bootloader.
So there you have it, you have now successfully unlocked the bootloader on your Samsung phone. You can now install a custom recovery such as TWRP and experiment with custom ROMs and whatnot.