How to flash Xiaomi Mi A3 on MIUI 12: a complete guide to unlock the bootloader

Xiaomi Mi A3

Android One

MIUI

MIUI 12

Xiaomi

The Mi A3 firmware on MIUI 12 is not officially supported, so the process involves risks ranging from loss of warranty to device blink. However, with the right approach, the chances of success are high. We will look at two main methods - through Fastboot and TWRP - and also tell you how to avoid typical errors. If you have never flashed a smartphone before, we recommend that you carefully study each section before you start work.

Important: MIUI 12 isn’t the last version of the shell for the Mi A3 (current for 2026 – MIUI 14), but it is the “twelfth” version that remains the most stable for this device.

1. Firmware Preparation: What to Do Before Starting

Before you start firmware, you need to follow a few critical steps, skipping any of them can make it impossible to restore the smartphone.

First, back up all your data. Fastboot or TWRP firmware completely erases your device's internal memory. Use Google Photos for media, Xiaomi Cloud for contacts and notes, and adb backup for apps and their data (instruction below).

Second, check the current firmware version and the device model. → Make sure you have a Xiaomi Mi. A3 (codename laurel_sprout), Not another model of the Mi A series. An error in choosing a firmware will lead to a "brick".

Third, prepare the equipment:

• 🔌 Cable USB Type-C (original or high-quality)
• 💻 Computer running Windows 10/11 (for Fastboot)
• 🔋 Battery charge of at least 60% (better than 100%)
• 📥 Downloaded Xiaomi drivers and utilities (Mi Flash Tool, ADB/Fastboot)

⚠️ Attention: If your Mi is yours A3 It was bought in Europe or India, check the firmware region. MIUI China (CN) This can lead to problems with Google services and 4G-We recommend choosing the right network. EEA (Europe) or Global.

2 Unlocking the bootloader: a step without which firmware is impossible

Xiaomi blocks the bootloader on all devices, including the Mi A3.Without it unlocking, installing MIUI via Fastboot or TWRP is impossible.The process takes between 72 hours and 1 week due to company policy.

To unlock, follow the following steps:

1. Link your Mi Account to your device: Go to Settings → Xiaomi Account Log in to your account (if not, sign up) Enable sync

• Open the Settings. → The phone.
• 7 times click on the MIUI version (yes, even if you have Android One)
• Back to Settings → Additionally. → For developers
• Enable USB Debugging and OEM Unlocking
• Connect your phone to your PC and confirm your debugging permission
• Download the official unlock utility (Mi Unlock Tool)
• Launch the utility, log in to your Mi Account and follow the instructions

Once you send an unlock request, you'll have to wait for confirmation. You can check the status on the same utility. When the bootloader is unlocked, the Unlocked will appear on the phone screen when you download it.

⚠️ Note: If you previously unlocked a bootloader on another Xiaomi device linked to the same account, the wait may be reduced to 24 hours).

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If the Mi Unlock Tool gives you a “Couldn’t verify device” error, try connecting your phone to another one. USB-port (preferably) USB 2.0 on the back of your PC or use the original Xiaomi cable.

3. firmware selection: which version of MIUI 12 to install on the Mi A3

For Xiaomi Mi. A3 (laurel_sprout) several firmware options available MIUI 12, Below is a table with current versions (checked for June) 2026):

For most users, the best choice is stable firmware EEA or Global. the Chinese (CN) versions are devoid of Google Play and other services, and custom firmware can contain errors.

Critical: Firmware for Mi A3 mi CC9e (Chinese equivalents are interchangeable, but only if they are the same version (laurel_sprout). Don’t confuse with the Mi firmware. A2 or Mi A1 — This will lead to a Brick"!

Downloaded the official version from the Xiaomi website|The file has an extension.tgz or.zip.|Archive size ~1.8-2.2 GB|MD5-The hash is the same as the one on the site.-->

4. Firmware through Fastboot: a step-by-step process

The Fastboot method is the most reliable for the Mi A3, because it doesn't require a customized Recovery, but it completely erases the data on the device.

Tools required:

• 🖥️ The Mi Flash Tool
• 📁 Firmware in.tgz format (unpacked in folder)
• 🔧 Xiaomi drivers for Fastboot (install automatically when connected)

Instructions:

1. Turn off the phone and press Volume Down + Power to log into the Fastboot.
2. Connect the phone to the PC.
3. Launch the Mi Flash Tool, press Select and specify the path to the firmware folder.
4. At the bottom, select Clean All (Full Cleaning) mode.
5. Press Flash and wait until the process is over (~5-10 minutes).
6. After successful firmware, the phone will restart automatically.

The first run after firmware can take up to 15 minutes — don't interrupt the process. MIUI For more than 20 minutes, perform hard reset (Loudness up) + Nutrition → Wipe Data).

5. Alternative method: firmware via TWRP

If you prefer the flexibility of a custom recavator, you can flash MIUI 12 through TWRP. This method allows you to save data (optional) and install additional modifications.

First, you need to install TWRP:

1. Download the current version TWRP for Mi A3 (laurel_sprout).
2. Rename the file to twrp.img and place it in the folder with ADB/Fastboot.
3. Turn on Fastboot on your phone (as in the previous method).
4. Run the command: fastboot flash recovery twrp.img
5. Immediately after that, do: fastboot boot twrp.img (this will load the phone into TWRP without overwriting the original Recovery).

Now install the firmware:

1. In TWRP, select Wipe → Advanced Wipe and select Dalvik, Cache, System, Data.
2. Go back to the main menu and select Install.
3. Specify the path to the firmware file (.zip).
4. Swipe for confirmation and wait for the end.
5. After installation, run Wipe Cache/Dalvik and restart.

⚠️ Note: If you are installing MIUI on top of Android One via TWRP, Do not use the "Format Data" option in the Wipe section, which will result in data encryption and no download. → Data and manually format the section.

6. Solving typical problems after firmware

Even with a successful MIUI 12 installation, Mi A3 users may encounter bugs, and here are some of the most common ways to fix them:

• 📵 No network (IMEI Fastboot: Fastboot command: Fastboot Flash modem NON-HLOS.bin (file NON-HLOS.bin It must be in the firmware archive. IMEI Not recovered, use the tool. QCN Rebuilder (requires backup) EFS).
• 🔋 Fast battery discharge: Calibrate the battery: completely discharge the phone, then charge to 100% Turn off the autobrightness and Wi-Fi/Bluetooth-Scan in settings. Install the Perseus kernel (for power users).
• 🎵 No sound in the speaker or headphones: Check the settings of the Sound → Audio Effects (disable all improvements) Refresh the vendor section: fastboot flash vendor vendor.img

If the phone does not turn on after firmware or hung on the logo, try:

1. Press Volume up + Power for 10-15 seconds (hard reset).
2. Fastboot reflash the device by selecting Clean all and lock mode (returns stock Recovery).
3. If nothing helps, use the EDL service (requires an authorized Xiaomi account).

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If Google Play or other services are missing after the firmware, you have installed MIUI for China (CN), so either run the EEA or Global version, or manually install GApps via TWRP.

7. rollback to Android One: how to return stock firmware

If MIUI 12 didn’t live up to expectations, you can return the original firmware Android One. A3.

Steps for rollback:

1. Download the Android One stock firmware (select the latest version).
2. Unpack the archive and put the files in a folder with the Mi Flash Tool.
3. Download your phone to Fastboot (Loudness Down + Power).
4. In the Mi Flash Tool, select Clean All mode and flash the device.
5. After restarting, reset to factory settings (Settings → System → Reset).

⚠️ Note: When you return to Android One, the bootloader will automatically lock. MIUI, Unlock it again before installing the stock firmware.

After the rollback, all Android One features will be restored, including monthly security updates from Google.However, note that some MIUI features (such as Second Space or Game Turbo) will become unavailable.

FAQ: Answers to Frequent Questions