How to flash Xiaomi Mi A3: official and custom firmware

The Xiaomi Mi A3 is one of the few smartphones of the brand released under the program Android One. This means that the device runs on “pure” Android without a MIUI shell, but also creates unique nuances when running firmware. Unlike classic Xiaomi models, there is no built-in EDL mode, and unlocking the bootloader requires a special approach.

Sweep Mi. A3 You can use several methods: Fastboot (for official firmware), Recovery (for customized ones). ZIP-files ADB Sideload (if standard recovery is not available) However, each method has its pitfalls, for example, after installing an informal firmware, Widevine may stop working. L1 (Netflix streaming will decrease, and improper unlocking of the bootloader can "brick" the device. In this guide, we will analyze all the current methods of firmware with the specifics of the Mi. A3 We can help you avoid typical mistakes.

Preparation for firmware: what to do before the start

Before you start firmware, make sure that all the preliminary steps are followed. Without them, the risk of turning a smartphone into a “brick” increases significantly.

First, check the bootloader version. A3 It can be locked even after unlocking through the official Mi Unlock Tool. To find out the status, turn off the phone, press the Volume down. + Power and look at the screen: if there's a Locked sign at the bottom, the bootloader is locked. MIUI (Yes, despite Android One, it still affects the firmware! → The phone. → Version. MIUI.

• 🔋 Battery charge at least 60 percent, and firmware can take up to 30 minutes, and it will fail in the process.
• 📥 Backup all data. Firmware erases internal memory, including photos, contacts and messages. Use Mi Cloud or Google Drive.
• 🖥️ Windows computer 7/10/11. Fastboot will require Qualcomm drivers and ADB. On MacOS or Linux, the process is possible, but more difficult.
• 🔌 Original. USB-Cheap cables may not be transmitting data in Fastboot mode, which will lead to errors.

Pay special attention to the choice of firmware. For the Mi A3, there are:

• 📦 Official firmware from Xiaomi (in.tgz format for Fastboot or.zip for Recovery).
• 🤖 Custom firmware (LineageOS, Pixel Experience, HavocOS) – require an unlocked bootloader and installed TWRP.
• 🔄 Port port MIUI — assemblies MIUI for Mi A3, Replace Android One with the familiar shell.

⚠️ Attention: If your Mi is yours A3 It was bought in China (the C-suffix version in the model), the firmware of the global version can block the network. → The phone. → Model.

Make a backup of data on Google Drive or computer|Check the battery charge (minimum) 60%)|Install drivers ADB and Fastboot on PC|Download the firmware for your model (laurel_sprout)|Connect the original USB-cable-->

Unlock the bootloader on Xiaomi Mi A3

Without unlocking the bootloader, you can’t flash the Mi A3 with custom firmware or even the official Fastboot. Xiaomi has made it harder for Android One devices, so the standard Mi Unlock Tool may not work the first time.

Here's the step-by-step instruction:

1. Link your Mi Account to your phone: Settings → Xiaomi Account → Sign in.
2. Activate debugging via USB: Settings → About Phone → Assembly Number (click 7 times), then Settings → System → For Developers → Debugging via USB.
3. Connect the phone to the PC, confirm the debugging permission.
4. Download Mi Unlock Tool (version no lower than 5.5.224.30).
5. Launch the utility, log in to the same Mi Account as on your phone.
6. Turn off the phone, press Volume Down + Power to log into the Fastboot.
7. Connect your phone to your PC, and the utility should detect it. Press Unlock.

If you have a Couldn’t unlock or Wait 360 hours error, you will be able to:

• 🕒 You recently linked your account to your phone (wait for 7 days).
• 🔄 You are using the wrong version of the Mi Unlock Tool (try 5.5.224.30 or later).
• 📱 Phone is not recognized in Fastboot mode (check drivers).

⚠️ Warning: Once the bootloader is unlocked, all data, including internal memory, will be reset, and Anti-Rollback protection may also work if you try to flash the old version of the software to the new one, in which case the phone will stop turning on.

Mi Unlock Tool from the first time | It took 7 days | Used alternative methods (EDL) | Could not unlock-->

Xiaomi Mi A3 firmware via Fastboot (official firmware)

The Fastboot method is suitable for installing official firmware from Xiaomi, which is the most reliable method, since the firmware is signed by the manufacturer and does not violate the integrity of the system, but it requires an unlocked bootloader.

Instructions:

1. Download the official firmware for Mi A3 (codename laurel_sprout) From en.miui.com. Choose the version of Fastboot (file.tgz).
2. Unpack the archive in the C:\platform-tools folder (where ADB and Fastboot are installed).
3. Turn off the phone, press Volume Down + Power to log into the Fastboot.
4. Connect your phone to your PC and launch the file flash_all.bat (for Windows or flash_all.sh (for Linux/Mac).
5. Wait for the process to be completed (about 5-10 minutes) and the phone will reboot automatically.

If the script is missing system.img or invalid sparse file, it means:

• 📁 The firmware archive is damaged (download again).
• 🖥️ The path to the firmware folder contains Cyrillic (transfer to the C:\).
• 🔧 Fastboot version is incorrect (update platform-tools to the latest version).

A critical feature of the Mi A3: If you are running a MIUI version older than 12.0.3, you may need to pre-installe the middle firmware (e.g. 11.0.8), or you will have an Anti-Rollback error.

fastboot flash boot boot.img


fastboot flash system system.img




fastboot flash vendor vendor.img




fastboot reboot

This will help to avoid errors with the script.-->

Install custom firmware through TWRP Recovery

Unofficial firmware installations (like LineageOS or Pixel Experience) will require custom TWRP recovery. There is no official TWRP for the Mi A3, so use informal builds from trusted developers (like from here).

Step-by-step:

1. Download TWRP.img for Mi A3 (version no lower than 3.6.1).
2. Move the file to the folder with the platform-tools.
3. Turn off the phone, press Volume Down + Power to log into the Fastboot.
4. Fastboot flash recovery twrp.img fastboot reboot recovery
5. In TWRP, make a full backup (click Backup, select all partitions except OTA).
6. Move it. ZIP-File custom firmware on the phone (via MTP into TWRP or OTG-cable).
7. Press Install, select. ZIP-file and confirm installation.
8. After installation, run Wipe → Format Data (required!), then restart.

Typical errors when installing custom firmware:

• 🚫 Bootloop means that the firmware is incompatible with your version of the bootloader.
• 🔒 Logo hanging -- maybe the Data partition isn't formatted. TWRP and execute Format Data.
• 📵 No network after firmware - custom firmware doesn't support your modem model. modem.zip.

Firmware via ADB Sideload (if Recovery does not work)

If standard or custom recovery is not started, you can flash Mi A3 through ADB Sideload. This method is suitable for formal and custom ZIP-firmware.

Instructions:

1. Download firmware in.zip format (for example, LineageOS or official). OTA-packet).
2. Turn off the phone, press Volume Up + Power to log in to Recovery (even if it's broken, ADB Sideload often works).
3. Select Apply Update → Apply from ADB.
4. Connect your phone to your PC and execute the command: adb sideload firmware.zip
5. Wait until the end (the progress will be displayed on the phone screen).

If it's 47% or 100% dead, don't turn off your phone! Wait 10 to 15 minutes.

• 🔌 Check the cable and port USB.
• 🖥️ Reset it. ADB Adb kill-server and adb start-server.
• 📦 Make sure that ZIP-File is not corrupted (check checksum) MD5).

Solving errors when firmware Xiaomi Mi A3

Even if you follow the instructions accurately, you can get errors, and the most common problems and solutions are listed below.

If the phone stops turning on (hard brick), the only option is to run through EDL (Emergency Download Mode) and this will require:

• 🔧 Authorized Xiaomi account (to access Mi Flash Pro).
• 📥 Firmware in.mbn format (special version for the EDL).
• 🔌 Contact closure cable (or tester for entry into the EDL).

⚠️ Attention: Firmware through EDL Without authorization, Xiaomi can block IMEI. Do not use the pirated versions of the Mi Flash Pro!

💡

If you lose your IMEI or network after you've run it, try to restore the modem by swiping nvdata.bin and nvram.bin files through Fastboot. These files can be extracted from the TWRP backup or official firmware.

How to check the success of the firmware

After you restart, you need to make sure that the firmware is installed correctly.

• 📱 Check the version of the software: Settings → The phone. → Android Version (for custom firmware) or Version MIUI (formal).
• 📶 Network test: Insert SIM-You can check the mobile Internet, the phone, if you don't have a network, you can swipe it separately. modem.zip.
• 🔒 bootloader status: Turn off the phone, press Volume down + Power. If you're reading Unlocked at the bottom of the screen, the bootloader is unlocked.
• 🎮 Performance: Run AnTuTu Benchmark or Geekbench to make sure the system is stable.

If there are problems after the firmware:

• 🔄 Restart your phone 2-3 times – sometimes the system stabilizes after a few reboots.
• 🧹 Reset settings through Settings → System system → Reset if lags are observed.
• 🔧 Reflash the phone with the same version of the software - perhaps the files were installed with errors.

FAQ: Frequent questions about the firmware Xiaomi Mi A3