How to block the bootloader on Xiaomi Redmi: 3 proven methods

The bootloader on Xiaomi Redmi smartphones is a software component that controls the launch of the operating system. It is blocked by the manufacturer by default to protect against unauthorized changes, but many users will unlock it to install custom firmware, root rights or modifications. However, there are situations when you need to return the factory lock - for example, before selling the device, to restore warranty or fix errors after unsuccessful experiments.

In this article, we will discuss the three official ways to lock a bootloader on Redmi (including the Note 12 Pro+, Redmi 10C, POCO X5 and others), their features and potential risks. It is important to understand that the procedure irreversibly deletes all data from the device and requires preliminary preparation. If you previously unlocked the bootloader through the Mi Unlock Tool, the process of returning to the factory settings will take no more than 10 minutes if you follow the steps correctly.

Why you might need to lock the loader

The main reasons why Xiaomi Redmi users decide to block the bootloader:

• 🔄 Warranty Restoration: Manufacturer refuses warranty repairs if bootloader unlocked, even if the breakdown is not related to software changes.
• 💰 Selling or transferring a device: the new owner may not be aware of the risks of an unlocked bootloader (vulnerability to viruses, complexity with the system). OTA-update).
• 🛠️ Fixing software failures: Some errors (e.g., cyclical reboot or problems with the software) MIUI) It is only possible to return to the factory state.
• 🔒 Security: Unlocked bootloader allows attackers to gain root access to the device without the owner's knowledge.

Important: locking the bootloader will result in a complete reset of the device (including internal memory).If the phone stores important data, pre-create a backup via Mi Cloud or locally on your PC. Also note that after blocking some functions (such as Google Pay or banking applications) may require reconfiguration.

Preparation of the device before blocking

Before starting the procedure, follow the mandatory steps:

Save important data (photos, contacts, messages)

Make sure that the battery charge is > 50%

Install the latest version of the Mi Unlock Tool

Download the official firmware for your model

Disable Mi Account protection (if you plan to sell your phone)-->

Pay special attention to the firmware version. If the device has custom firmware (for example, LineageOS or Pixel Experience), first return to the stock MIUI via Fastboot. Otherwise, locking the bootloader can lead to a "brick" (inoperability) of the device.

⚠️ Note: If you previously linked your Mi Account to your device but forgot your password, it will be impossible to unlock your phone after locking the bootloader! Make sure you remember the login details or untie your account in advance in the Mi Cloud settings.

Method 1: Locking through Mi Unlock Tool (official method)

This is Xiaomi’s most reliable and recommended method, and it’s suitable for most Redmi models released after 2018.

• 🖥️ Windows computer 7/10/11 (64-bit).
• 🔌 Cable USB (preferably original).
• 📱 Device with unlocked boot loader and enabled mode OEM Unlock.

Step-by-step:

1. Download the latest version of the Mi Unlock Tool from the official website and install it on PC.
2. Run the program on behalf of the administrator and log in under the same Mi Account that is linked to the phone.
3. Turn off Redmi and press Volume Down + Power to enter Fastboot mode. Connect the device to your PC.
4. In Mi Unlock Tool, press Unlock (yes, “unlock” – the program automatically detects that the bootloader has already been unlocked, and prompts you to block it back).
5. Confirm the action and wait for the process to be completed (usually takes 1-3 minutes).

If the program gives you a "Couldn't unlock" error, check:

• 🔹 The correctness of the Mi Account.
• 🔹 Availability of an active Internet connection on PC.
• 🔹 No antivirus that blocks the Mi Unlock Tool.

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If the Mi Unlock Tool does not recognize the device, try installing Xiaomi drivers manually through Device Manager (Other Devices section).

Method 2: Blocking through Fastboot commands

This is a good way for experienced users who are familiar with ADB and Fastboot, and it is useful if the Mi Unlock Tool doesn’t work or it gives you bugs.

You will need to:

• 🖥️ PC with installation ADB/Fastboot (You can download it through Android Studio).
• 📱 Phone in Fastboot mode.
• 📄 Firmware file for your model (download from the official website).

Instructions:

1. Unpack the downloaded firmware in the folder from fastboot.exe.
2. Open the command line (Win + R → cmd) and go to the folder with the firmware: cd C:\path\folder\s\firmware\s\firmware
3. Connect your phone in Fastboot mode and execute the command to check the connection: fastboot devices If the device is displayed, continue.
4. Start the lock process: fastboot oem lock Confirm the action on the phone (if you receive a request).
5. After blocking, flash the stock firmware: fastboot flash all This will delete all data and return the device to factory state.

⚠️ Warning: If the phone stops turning on ("brick") after the fastboot oem lock command, don't panic. Connect it to your PC and run the full firmware through the Mi Flash Tool in Clean All mode.

Method 3: EDL-Blocking (for "blocked" devices)

If Redmi doesn't turn on or is stuck on the MI logo, but the bootloader has been unlocked, you can try to restore it via EDL (Emergency Download Mode).

• 🔧 Special cable. EDL (or circuitry).
• 💻 Mi Flash Tool and Firmware for Your Model.
• 🔑 Authorized Xiaomi Account (for new models).

Step-by-step:

1. Download and install the Mi Flash Tool (available on the official website).
2. Put your phone in EDL mode: For working devices: turn off your phone, press Volume Up + Volume Down and plug in a USB cable. For "bricked": disassemble your phone and close the EDL contacts (usually points labeled TEST POINT next to the battery).

In the Mi Flash Tool, select the downloaded firmware and press Refresh. The device must determine how to use the device. COM-port.

Select Clean All and Lock mode (this will automatically block the bootloader after firmware).

Press Flash and wait until it is completed (the process can take 5-15 minutes).

After successful firmware, the phone will reboot with a locked bootloader and a clean MIUI.

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EDL mode is the last chance to restore a “bricked” device. If Xiaomi blocked authorization for your model (for example, on Redmi Note 11 and later), you will need an official authorized account or help from a service center.

Compatibility table with Xiaomi Redmi models

Not all ways to lock the bootloader work on all devices, and here is a compatibility table for popular models:

If your model is not in the table, check it on the official Xiaomi website in the firmware section. For devices from 2023 to 2026 (for example, Redmi Note 13), additional authorization through the service center may be required.

Frequent mistakes and their solutions

When blocking the bootloader, users often face the following problems:

• 🔴 Mi Unlock Tool Solution: Check the Mi Account's link to the device. If the phone was bought from hand, the previous owner must untie his Mi Cloud account.
• 🔴 Phone is not defined in Fastboot Solution: Install drivers manually or use another cable/port USB. On some PCs, disabling driver signatures helps.
• 🔴 After locking the phone does not turn on ("brick") Solution: Sweat the full firmware through the Mi Flash Tool in Clean All mode. EDL.
• 🔴 Anti-rollback error when firmware Solution: Download firmware with version MIUI Information about the current version can be found in Fastboot by the command fastboot getvar all.

⚠️ Note: If after blocking the bootloader phone requires the entry of a password from Mi Account, but you do not remember it, you can restore access only through the official service Xiaomi (you need a check about the purchase.

FAQ: Answers to Frequent Questions