If you're thinking about Install a custom ROM, root your device, or install a custom recovery. On your Xiaomi, Samsung, or Google Pixel phone, there's one step you can't skip: unlocking the bootloader. It's the guardian of the system's startup, and while it's locked, the manufacturer prevents you from accessing the phone's deeper software.
Unlocking it opens the door to a lot of possibilities, but it also involves certain risks: All the content on your phone is erased, some security is lost, and it's easy to mess things up if you don't follow the steps carefully.Here you will find a detailed guide, in Spanish (Spain) and without unnecessary technical jargon, to understand what the bootloader is, what unlocking it entails and how to do it on Xiaomi, as well as general considerations for Samsung and Pixel.
What is the bootloader and why is it locked?
Every Android phone has a small program that takes care of to start the system every time you turn on the phoneThat program is the bootloader or boot manager. It decides which system to load, when to reboot, enter recovery mode, or launch fastboot mode if it detects problems.
Beyond that function invisible to the user, the bootloader also controls What type of software can be loaded onto the device?If it's locked, it only allows you to run official versions signed by the manufacturer. If it's unlocked, it lets you load custom ROMs, modified recoveries, and alternative kernels.
Manufacturers like Xiaomi, Samsung, or Google include a factory-locked bootloader. to prevent anyone from modifying the system and compromising the security of the deviceThis way they reduce the risk of deep malware, comply with security certifications, and better control updates.
In the specific case of Xiaomi (including Redmi and POCO), all phones come with a locked bootloader. The idea is to prevent the installation of unauthorized ROMs, avoid unwanted rooting, and make system manipulation more difficult. in case of theft or loss.
The good thing is that Xiaomi, unlike other manufacturers, offers an official procedure to unlock the bootloader, with its own tool (My Unlock) and a system of permissions and waiting times designed as an additional layer of security.
Risks and consequences of unlocking the bootloader
Before you begin, it's essential to understand what this process entails. Unlocking the bootloader is not a simple, insignificant adjustment: It directly affects the security of your mobile phone and completely erases all your data..
The first thing you must assume is that Unlocking resets the phone to factory settingsPhotos, videos, conversations, apps, settings, documents… everything is deleted. If you don't make a backup beforehand, you lose it all. It's that simple.
Furthermore, an open bootloader means a potentially vulnerable device more vulnerable to attacks or unauthorized accessEspecially if someone with physical knowledge has the phone in their hands. That's why manufacturers emphasize that this process is done at your own risk, and a warning usually appears stating that the device will be less secure.
In many models, unlocking the bootloader causes a warning or error message to appear at startup. open padlock icon indicating that the boot manager has been unlocked. This is a way for the user and technical support to know that the system has been modified or is modifiable.
Another common consequence is that Certain security functions are disabled, such as some mobile payment systems or integrity checks (SafetyNet, Play Integrity, etc.), which may stop working properly if they detect an unlocked bootloader or an uncertified ROM.
What you need to prepare before you start
If you're sure you want to move forward, it's best to prepare the ground well. A serious breakthrough isn't something you do hastily. Take a few minutes to get everything ready and reduce surprises.
On a Xiaomi device, to use Mi Unlock you will need a Windows computer (it can be in a virtual machine if you're familiar with the topic), a USB cable in good condition and official Mi Unlock appwhich can be downloaded from the MIUI website. Install it and have it ready before you start using the phone.
Make a full backup of anything you don't want to lose. You can use My Cloud, Google Drive, export photos to your PC, save contacts to your Google account or a VCF fileand back up chats from messaging apps. Remember: the unlocking process will leave your phone like new.
It is also advisable to have on hand your Xiaomi account login details (email, phone, password) or the corresponding account if we're talking about Samsung or Pixel, because you'll need them to link and authorize the process.
And one last detail that often goes unnoticed: check that the mobile phone has sufficient battery, ideally more than 60%You don't want it to turn off in the middle of an unlock or flashing process because then you could render it unusable.
How to unlock the bootloader on Xiaomi phones step by step
At Xiaomi, the procedure is fairly standardized and revolves around two key elements: your Mi account and the Mi Unlock toolBroadly speaking, the process has two phases: requesting or verifying permissions and executing the unlock itself.
For a long time it was necessary to Send a manual request to Xiaomi You would explain why you wanted to unlock your device, wait for the request to be approved, and receive a confirmation SMS. Today the system has been simplified, but there are still cases where that approval step and wait of several days (or even more than two weeks) is required.
In the "classic" version of the process, when Xiaomi asks for the unlock reason, it is important Do not copy and paste designs taken from forums or tutorials.Many users report having their requests rejected precisely because they used repetitive text. Ideally, you should write a simple, original explanation, preferably in English, such as "I want to unlock to install custom ROMs and use root tools."
Once you apply for the permit, all that remains is wait for the approval SMSThis can take quite a while. Some users receive the message within a few days with texts like “You have granted permission to unlock device.” This means that, in theory, your account is now authorized to unlock the bootloader with Mi Unlock.
There have also been many cases where the SMS never arrives but the account is still approved. In these cases, Trying to use Mi Unlock directly won't break anythingIf you do not have permissions, the tool will indicate this and will not proceed.
Activate developer options and Mi Unlock on your mobile device
Before using the PC, you need to prepare your phone. The first step is to activate the hidden developer menu, which is where you'll find... the My Unlock status option in MIUI.
To do this, go to SettingsGo to the top where it says “About phone” and tap on it. Inside, find the “MIUI version” section and tap on it several times in a row, usually between five and seven touchesYou will see a message indicating that developer options have been enabled.
When you receive the notification that “Developer options are now enabled,” return to the main Settings screen. Now scroll down to "Additional settings" and enter. The "Developer options" section should appear in this menu.
Within that developer menu, look for the option “My Unlock Status”This is where the link between your device and your Mi account is managed to enable unlocking. The first time you log in, MIUI will display a notification requesting permission to access your account, your ID, and to collect data such as the IMEI or IMSI.
In order for the system to properly verify the device, it is necessary that Turn off WiFi and use your mobile data connection When you go to add the account in "My Unlock Status", many users encounter errors such as "Verification failed. Please add your account and device again" because they have Wi-Fi enabled.
Link your mobile phone to Mi Cloud and check that it is online.
A key step that is sometimes overlooked is the correct Link your phone to Mi Cloud with the same account you'll use for Mi UnlockIf this is not done correctly, the PC tool may complain or simply not allow the process.
On mobile, go to Settings → My AccountAt the top, you'll see your username (name or number assigned by Xiaomi). Tap on it to access your account details. Make sure you have an account associated with your account. your phone number and a verified email addressIf any are missing, add them: they will usually ask you to verify your email before allowing you to link your number.
Go back one step within the account and access We CloudScroll down and locate the "Find Device" option. Activate it. The system may send an international SMS to register the service, which is necessary to ensure everything is properly linked.
Now, from a computer, go to the official Mi Cloud website: https://i.mi.comSign in with your Mi account. In many cases, Xiaomi assigns a number to the account, which you can also use as your username. Once logged in, tap the button to connect your phone. They will send you a code via SMS that you will have to enter on the website..
If everything goes well, at the top of the website you will see that the mobile appears as connected and in "online" status in My CloudIt's important that you only associate the device you're going to unlock in Mi Cloud, because some users have had problems having multiple devices synced at the same time.
Use Mi Unlock on your PC to unlock the bootloader
With your account linked and your mobile device ready, it's time to switch to your computer. Open the application. My Unlock in Windows and sign in with the same Mi account details you used on your phone and Mi Cloud.
Now completely power off your Xiaomi phone and boot it into fastboot mode. To do this, press and hold the following buttons simultaneously: volume down and power button until the fastboot logo appears on the screen (usually the Mi figure with an Android).
With the phone in fastboot mode, connect it to the PC with the USB cable and wait a few seconds for Windows to load. Recognize the device and install the driversWhen Mi Unlock detects the device, the “Unlock” button will become active (usually it appears in green).
Press on “Unlock” within Mi Unlock. The app will show you a series of warnings about data loss, security risks, and potential implications. Read them carefully and accept if you agree and want to proceed.
At that moment, My Unlock will check that Your account and device are eligible for unlocking.It will then send a request to Xiaomi's servers. The screen will show you how long you'll have to wait before the final unlock is completed: usually several dozen hours, with typical cases taking around seven days, although some report up to 70 hours or more as an extra security measure.
Waiting, retries, and common problems with My Unlock
Once the process has started, comes the boring part: waiting for the time specified by Xiaomi. During that period, the phone It will not send you any notifications. You won't receive a notification that you can finish unlocking your device, nor will you receive a specific SMS message. You'll need to note the remaining time and remember to try again yourself.
When you think the deadline has passed, repeat the steps: Fastboot mode, connect via USB, open Mi Unlock, log in and press “Unlock”If the required time has not yet elapsed, the tool will tell you how many hours or minutes are left.
It is important to always remember that When the process is finally complete, the mobile phone will be completely erased.restoring it to its factory settings. That's why it's so crucial not to forget previous backups.
Some users encounter error messages such as “Verification failed. Please re-add your account and device” when accessing “My Unlock Status.” In these cases, it often helps to... Repeat the account linking process using mobile data, reactivate Find My Device, and restart the device.Sometimes, Xiaomi's servers are simply overloaded or experience occasional problems.
Another common message in Mi Unlock is “Your device isn't supported by Mi Unlock” or warnings that The Mi account does not have permissions, has been rejected, or needs more activity. Xiaomi even shows texts like "Sorry, your application has been rejected. The more active your Mi Account is, the more likely your application will get approved."
What to do if your unlock request is rejected
When Xiaomi rejects the request or tells you that your account cannot unlock the device, there are several possible explanations. One of the most widespread theories is that They don't like it when the account is inactive for months or when the reason submitted is a copy and paste from the internet.This is something that is being discussed in forums and could even lead to a block on access to My Unlock.
One solution that many have followed is to create a New Mi account with different details: new phone number, new email address, and new passwordThen, request the unlock again with this new account and repeat the SMS waiting process.
In parallel, it is usually recommended Install an official ROM, preferably the latest global developer ROM. of your model, using Mi Flash or TWRP if you already had it, but always remember to log out of your old Mi account before changing ROMs and also log out of Mi Cloud from your PC.
If the new ROM forces you to use the old account, complete the boot process with that account, go into settings and Log out by selecting the option to erase the data on that device.Next, log in to your phone and Mi Cloud with the new account, making sure that your mobile and cloud are properly synchronized and that only that associated phone appears in Mi Cloud.
Once that's done, reopen Mi Unlock on your computer, log in with the new account, and repeat the process. Many users report that by following this method, they have regained the ability to unlock even after previous rejectionsIf you continue to have problems, another option is to write directly to [email protected] explaining the case and attaching relevant data, although the response may take weeks.
Check if the bootloader is unlocked and how to relock it
Once Mi Unlock completes the process and the phone restarts, you will notice upon turning it on that the initial boot screen appears an icon or text indicating that the bootloader is unlockedusually an open padlock or a security warning.
For more technical confirmation, you can use fastboot mode and a computer. With your phone in fastboot mode and connected via USB, open a command prompt window on your PC and type fastboot oem device-infoThis command will return information about the device status, indicating whether the bootloader is “true” (unlocked) or “false” (locked), depending on the manufacturer.
In the case of Xiaomi, if at any point you want to return to lock the bootloader After installing an official ROM, you can also do it using fastboot commands or specific tools, as long as you keep the original Xiaomi recovery and use a genuine ROM. Locking the bootloader with a custom ROM can cause a serious brick.
There are also those who re-lock it using tools like Mi Flash with official firmware and selecting the "clean all and lock" options. In any case, Re-locking is recommended when you're no longer going to use custom ROMs. and you want to restore the phone to its original security level.
Unlocking the bootloader on Samsung and Google Pixel: general considerations
Although this guide focuses mainly on Xiaomi, Samsung and Google Pixel have their own approach when it comes to allowing bootloader unlocking and the installation of custom ROMs or recoveries. The concept is the same, but the steps and restrictions vary considerably..
On many recent Samsung phones, especially the Snapdragon processor variants sold in certain markets, the bootloader is blocked much more strictlySome models do not allow official unlocking at all, while others allow it by activating "Developer options" and using settings such as "OEM unlocking".
Google Pixel phones, on the other hand, are more community-friendly. On most models, simply activating the feature is enough. Developer options, enable “OEM unlocking” and USB debugging modeReboot into fastboot mode and use fastboot commands from your PC to unlock the bootloader. The official process is better documented and is usually more straightforward.
In both Samsung and Pixel, it is common that, when unlocking the bootloader, all data on the device will be erasedJust like on Xiaomi. In addition, warnings will appear stating that the system is less secure, startup will display warnings, and certain security or payment features may be disabled.
In all cases, it is advisable to review the official documentation for the specific model and, above all, the specialized forums for your device (XDA, HTCMania, brand's own forums) to follow a step-by-step tutorial adapted to the exact device, since small hardware or region changes can completely alter the procedure.
Ultimately, unlocking the bootloader, whether on a Xiaomi, a Samsung, or a Pixel, is a decision best taken carefully: It opens up a world of possibilities for customizing your mobile phone and recovering a stuck or boot-loop device.But it requires accepting data loss, lower security guarantees, and the need to be well informed before each step to avoid ending up with an expensive brick in your hands.