Unlocked bootloader: Top 4 brands you should choose! 📱🔓

Many manufacturers permanently lock down the phone's hardware, preventing you from making system-level changes. If you're an Android lover interested in experimenting with your device, consider these brands first. 📱🔧

What is an unlocked bootloader?

When you turn on a powered off Android phone, it doesn't boots directly into the operating system Android. There is a quick transfer in the blink of an eye before the operating system is loaded on the device.

What exactly is the bootloader?

The first code that is executed is built directly into the system in the chip, the chip that houses the CPU, GPU, and RAM. So this code, embedded in the hardware, activates the CPU, storage and RAM. It cannot be modified as it is recorded in the hardware itself (technically it is called ROM or read-only memory).

Este código incorporado activa otro programa, que a su vez carga el sistema operativo Android. Este segundo programa puede ser modificado porque se guarda en el almacenamiento regular.

To quickly recap before we move on: a hardware program powers up the CPU and RAM, and then activates another program that loads everything else. Together, these two programs make up the “bootloader.” The first program (the unmodifiable one) is the primary bootloader, and the second (which can be modified) is the secondary bootloader.

It seems simple, but what does it mean when a bootloader is locked or unlocked? 🤔

Why do they lock the bootloader?

Imagine a scenario where someone replaces your full operating system for one copy identical but full of bugs. You would have no way of knowing that someone had tampered with your device. How do you ensure that the phone never loads a compromised version of the operating system?

One answer is this: you embed the first program that runs directly on the hardware. That way, it's tamper-proof, and you have a reliable starting point (the primary bootloader, in this case). Then, a larger program is launched from the phone's regular storage, which verifies the integrity of the entire operating system (the secondary bootloader).

Since this secondary bootloader is in the phone's writable memory, it can be modified. So, someone could bypass the boot verification (which the secondary bootloader performs) to load a version unsigned and unofficial bootloader or any other operating system that the hardware supports. To prevent this from happening, manufacturers "lock" the secondary bootloader. In its locked state, the “Verified Boot” feature only allows Android versions officially signed.

Now, we can answer the original question. Some manufacturers allow you to “unlock” the bootloader and disable the “Verified Boot” feature. In its unlocked state, the phone can load any device. operating system installedIt doesn't have to be Android. Depending on the phone manufacturer, unlocking the bootloader can be easy, difficult, or downright impossible.

What can you do with an unlocked bootloader?

With an unlocked bootloader, you can do some pretty cool things. For example, you can get root access to your device. By default, phone manufacturers allow you to gain root access to your device. Android only gives us minimal access to our devices. We cannot make system-level changes or install applications with root (or administrator) privileges. That is the reason why you cannot remove those apps factory pre-installed.

Removing bloatware only scratches the surface of what is possible with an unlocked bootloader. You can even backup your data security complete device image captures of its full state. With backups full-image, I mean that every setting, app and file, down to the current wallpaper, can be backed up and restored.

In the early years of Android, there were vibrant communities of developers and enthusiasts dedicated to modifying Android phones. They released custom versions of Android like LineageOS (called CyanogenMod back then), custom versions of the Android kernel, a bunch of tweaks, and more. system level performance and advanced topics.

Back then, a single tap was enough to unlock or relock a bootloader. As Android matured and manufacturers made it harder to unlock bootloaders, those communities faded away. You can still find and install custom ROMs and root most popular Android phones.

Nowadays, most developers and hardcore enthusiasts are concerned with modifying Android. Now you can see how you can only fully access your phone if the manufacturer does not permanently lock the bootloader.

Phone brands that offer easy bootloader unlocking

Here is the list of brands I would buy from if I wanted to experiment with my device. You can also do your own research. My only advice is to not buy a Samsung if you plan to unlock the bootloader. Samsung US variants are impossible to unlock.

Google Pixel

If you buy a Pixel phone directly from Google, it is easy to unlock your bootloader. Just enable the “OEM Unlocking” switch in the settings, boot into Fastboot and run the correct ADB command. I wrote a detailed tutorial to unlock bootloaders.

Pixels also receive the best community support. Almost all custom ROMs Main features are supported on Pixel phones; some, like GrapheneOS, are exclusive to Pixel. Reddit and the XDA Forums have very active Pixel communities.

If you buy your Pixel through a carrier, this can get a little tricky. Depending on the carrier, access to the bootloader may be restricted until your contract ends.

Xiaomi

Bootloaders on Xiaomi phones are also easy to unlock. In fact, Xiaomi provides a unlock tool Any Xiaomi device. On average, Xiaomi phones (at least the high-end models) get a lot of support on forums. So, if you're buying a phone just for experiments but don't want to spend a thousand dollars on a Pixel, a budget Xiaomi is your best bet. 💰

Sony

Sony has a official tutorial on their support page showing how to unlock the bootloader on Xperia phones. Apparently not all phones Sony can be unlocked, but you can check the Developer World page on Sony's website to find out if your device supports bootloader unlocking and how to do it.
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Sony

The Xperia 1 V on a stylised background.

Motorola

Motorola has a dedicated page to assist you with the unlocking of your bootloader. If you buy directly from Motorola, you should not have Problems with most modern Android models, including the latest Razr series.

Unlocking the bootloader has serious risks (Read the fine print)

Since the bootloader is responsible for verifying the integrity of the entire operating system, disabling that feature security makes your phone more vulnerable. 🔒

Second, unlocking the bootloader almost always voids your warranty, and manufacturers repeatedly warn that they will not cover an unlocked phone. Even if you manage to relock the bootloader later, they can still see that it was unlocked at some point, which voids your warranty. I suggest you only unlock a phone if it is already out of warranty.

Often, Unlocking the bootloader also wipes the phone to factory settings factory reset. So before you try to change the bootloader, always do a backup your data. 💾

Finally, be careful when installing custom operating systems or by gaining access root. Flashing the wrong file can render your phone unusable, sometimes permanently (RIP my Samsung Galaxy S4). Also, banking and finance apps may not work properly on a rooted phone.

Most manufacturers no longer allow you to unlock your phone's bootloader. So, if you are an experimenter or an enthusiast who wants to have full access to the hardware you paid for, I recommend buying a brand that supports bootloader unlocking.