Installation MIUI 12 on Xiaomi Mi Max 3: official and custom methods

Why MIUI 12 should be installed on the Mi Max 3?

Xiaomi Mi Max 3 is a favorite among users who appreciate the large screen and long-term autonomy, but over time, even this giant begins to “slow down” on older versions of MIUI. Updating to MIUI 12 promises not only a fresh design with animations based on Android 10/11, but also performance optimization, new features like Super Wallpapers and improved multitasking. However, official support for the Mi Max 3 (codename nitrogen) has long been discontinued, and therefore – will have to act manually.

In this article, we will discuss all the current ways to install MIUI 12: from official firmware (if it is still available for your region) to custom builds based on MIUI EU or xiaomi.eu. Particular attention will be paid to unlocking the bootloader without waiting for 720 hours - this is a key step that many miss. Also discuss the risks, backup important data and what to do if after the firmware phone stops loading.

We warn you right away that the process requires attention to detail. One wrong action, and you risk getting a brick. But if you follow the instructions Step-by-step, even the beginner can do it in 30 to 60 minutes. Let's start with preparation!

1. Compatibility check and device preparation

Before you download the firmware, make sure your Mi Max 3 complies with the requirements. MIUI 12 officially supports only devices with an unlocked bootloader and the current version of MIUI 10/11 as the base. If you have an older firmware (such as MIUI 9.6), first upgrade to the intermediate version through Settings → About Phone → System Update.

Critical points to check:

• 🔋 Battery charge at least 60 percent. It can take up to 20 minutes to run the firmware, and if the phone turns off in the process, the consequences will be dire.
• 📱 Model of the device - confirm that you have Xiaomi Mi Max 3 (nitrogen). → The phone. → Model.
• 🔓 bootloader status – if it is blocked, unlocking will take up to 30 days (more in the next section).
• 💾 Backup: Copy photos, contacts and apps on your PC or in the cloud!

Also prepare:

• 🖥️ Windows computer 10/11 (for the Mi Flash Tool or Linux/macOS (for fastboot in the terminal).
• 🔌 Cable USB Type-C original or high-quality (cheap cables can interrupt data transmission).
• 📂 Firmware MIUI 12 for nitrogen (references to verified sources - in section 3).

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If you have root or custom recovery installed (TWRP), before-fixing MIUI 12 You can also remove them through fastboot flash recovery. stock_recovery.img. Otherwise, the system can fixate on the Mi logo.

2. Unlock the bootloader: bypass the 720-hour limit

The hardest part is unlocking the bootloader, which Xiaomi has introduced to protect against fraud, but for Mi Max 3 owners, it has been a real headache. The official way is to tie the Mi Account to the device and wait 30 days (720 hours), but there are workarounds — legal and not very.

The official method (for the patient):

1. Link your Mi Account to your phone in Settings → Xiaomi account.
2. Activate the OEM unlock option in Settings → Additional → For developers.
3. Run Mi Unlock Tool on PC, log in to the same account and follow the instructions. The program will show a countdown timer.

Unofficial methods (at your own risk):

• 🔄 Resetting the timer through a change in Mi Account (it does not always work, can block the device).
• 🛠️ Use of Mi Unlock Tool (Ban Account Risk).
• 📱 Buying an unlocked phone in the secondary market (check statuses through fastboot oem device-info).

⚠️ Note: If you have used informal unlock methods, before the firmware MIUI 12 be sure to check the bootloader status with the command: fastboot getvar unlocked The answer should be unlocked: yes. Otherwise, the firmware will end with a Critical Partition Flashing Not Allowed error.

3. firmware selection: official vs custom MIUI 12

For Xiaomi Mi Max 3, there are several types of MIUI 12 firmware available.

For most users, the best choice is MIUI EU. It retains all the chips of the original shell, but removes Chinese services and advertising. download only versions marked nitrogen (codenamed Mi Max 3) and check check checksums (MD5) after download.

How do you check the checksum? Use the md5sum utility in the terminal or the HashMyFiles program for Windows.

md5sum miui_NITROGEN_20.12.10.zip

Must match the MD5 on Xiaomi.eu

Download firmware for the model Nitrogen|Check it out. MD5-hash|Unpack. ZIP cyrillic|Disable the antivirus (can block fastboot)|Connect your phone to your PC in Fastboot mode-->

4. Step-by-step instruction: installation via Fastboot

Fastboot is the most reliable method for installing MIUI 12, as it sifts through all partitions, including boot and recovery. It is suitable for official and custom firmware.

Step 1: Transfer your phone to Fastboot mode

1. Turn off the Mi Max 3.
2. Press Volume Down + Nutrition for 10 seconds until the hare appears in the hat-eared.
3. Connect your phone to your PC. Android Bootloader Interface should appear in the Device Manager.

Step 2: Firmware via Mi Flash Tool

1. Download and install the Mi Flash Tool.
2. Unpack the firmware into a folder without spaces (e.g., C:\MIUI12\nitrogen).
3. In Mi Flash Tool, click Select, specify the folder with the firmware.
4. Select Clean All or Clean All and Lock (if you want to lock the bootloader after you have been firmware).
5. Press Flash and wait until it is completed (10-15 minutes).

Step 3. First download

After a successful firmware, the phone will restart. The first turn on can take up to 10 minutes - don't interrupt the process! If the screen has been getting stuck on the Mi logo for longer than 20 minutes, try:

• 🔄 Go to Recovery (Loudness Up) + Power) and make Wipe data.
• 🔧 Reflash by selecting Save user data (if available).

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Clean all mode in the Mi Flash Tool erases all data, including internal memory. If you want to save files, pre-copy them on a PC or on a computer. SD-map.

5. Installation via Recovery (TWRP)

If you prefer custom firmware (e.g. MIUI EU), TWRP Recovery is more convenient, which retains more control over the process and allows you to make backups.

Step 1: Installation of TWRP

Download the latest version of TWRP for nitrogen from the official website and go through fastboot:

fastboot flash recovery twrp-3.6.2_nitrogen.img


fastboot boot twrp-3.6.2_nitrogen.img

Step 2. MIUI 12 firmware

1. Copy. ZIP-firmware file on the phone or SD-map.
2. In TWRP, select Install → Select ZIP → Swipe to confirm.
3. After installation, run Wipe → Format Data (required!), then restart.

Step 3: Correction of errors

If there is no network after firmware or sensors do not work, try:

• 📶 Switch modem and vendor from official firmware via fastboot.
• 🔄 Make a full reset in TWRP (Wipe → Advanced Wipe → Dalvik, Cache, Data, System).

⚠️ Attention: Some assemblies MIUI EU You need additional Magisk firmware to work properly with Google Pay and banking applications.Install Magisk only after the first successful system boot!

6. Solving common errors

Even with the correct following of the instructions, problems can arise, and here are the most common ways to solve them:

If none of the methods worked, go back to the official firmware via the Mi Flash Tool in Clean All and Lock mode, then repeat the process from the start.

Where can I find help?

• 📖 Official documentation: MIUI Downloads
• 💬 Forum XDA Developers: Mi Max 3 section
• 📢 Telegram chat MIUI Russia: @miuirus

7. optimization of MIUI 12 after installation

After successful firmware, set up the system for maximum performance and autonomy:

1. Disable unnecessary services:

• 🚫 Settings → Annexes → Application management → Auto-Start – Disable for Unnecessary Programs.
• 📵 Settings → Battery → Energy Saving Mode – Choose Balanced.
• 🔔 Settings → Notifications – Disable notifications from Mi Video, Mi Browser, and other standard apps.

2. Install important updates:

• 🔄 Check the Settings. → The phone. → Updating the system for security patches.
• 🛡️ Install Magisk (if you need root) through TWRP.

3. Restore the data:

If you backup through TWRP or Mi Cloud, restore contacts, SMS and apps. For photos and files, copy them back to your phone via MTP (a USB connection).

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To speed up MIUI 12, turn off animations: go to Settings → About Phone, tap 5 times on the MIUI Version, then set Windows Animation = 0.5x and Transition Animation = 0.5x in the Developer Settings.

FAQ: Frequent questions on MIUI 12 Mi Max 3