How to flash Xiaomi Redmi Note 12: official and custom methods

The Xiaomi Redmi Note 12 is one of the most popular mid-range smartphones, but even it isn’t immune to software glitches, slowdowns, or the user’s desire to install custom firmware.The device’s firmware can solve performance problems, add new features, or even bring the phone back to life after a failed upgrade.

In this guide, we will analyze all the current ways to implement the Redmi Note 12 firmware (including the Pro, Pro+ and 4G/5G models), from official updates via MIUI Updater to install custom builds via TWRP or Fastboot. We will pay special attention to unlocking the bootloader - a mandatory step for most methods, and also warn against typical errors that beginners make.

Preparation for firmware: what you need to know before you start

Before you start firmware, make sure you understand the risks and consequences. Official updates through MIUI Updater are usually safe, but even they can lead to data loss if you don't back up. Custom firmware (like LineageOS or Pixel Experience) require unlocking the bootloader, which resets the device to factory settings and voids the warranty (if it's still valid).

Here’s what you should check before the firmware:

• 📱 Device model: Refine the exact modification (Redmi Note 12) 4G, Note 12 Pro 5G etc.), because firmware is not universal. Find it in Settings → The phone. → Model.
• 🔋 Battery charge: At least 60% – firmware can take up to 30 minutes, and discharging in the process will lead to failure.
• 💾 Backup: Save contacts, photos and important files on your PC or in the cloud. Use Mi Mover or Google Drive.
• 🔗 Cable and PC: For Fastboot methods or ADB You'll need an original USB-cable (not a cheap replacement!) and a computer with Xiaomi drivers installed.

Critical detail: Fastboot erases all data, including internal memory (including the DCIM folder with photos!). Even if you upgrade on top of your existing system, the risk of data loss remains.

Official Firmware Methods: MIUI Updater and Recovery

If your goal is to upgrade the Redmi Note 12 to the latest version of MIUI without risking losing the warranty, use built-in tools.This method is suitable for fixing bugs or getting new features from Xiaomi.

Method 1: Update with MIUI Updater (OTA)

The easiest way to do this is to not unlock the bootloader or connect to the PC:

1. Open Settings → About the phone → System update.
2. Click Check Updates. If a new version is available, download it.
3. After download, click Set and wait for the reboot.

If the update doesn’t come automatically, try clearing the System Update app’s cache in Settings → Apps.

Method 2: Installation through Recovery

If OTA-Update does not work (for example, due to corrupted files), you can install firmware manually through Recovery:

1. Download the official ROM for Recovery from MIUI Downloads (select your model!).
2. Rename the file to update.zip and move it to the root of internal memory.
3. Turn off the phone, then press Volume Up + Power to enter Recovery.
4. Select Install update.zip and confirm the installation.

Attention, not all versions. MIUI Recovery supports custom installation ZIP-If you're trying to flash informal firmware, it's not going to work, it's going to work. TWRP.

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If your phone is stuck on the MI logo after you upgrade via Recovery, wait 10-15 minutes. Sometimes the first download takes a long time due to app optimization.

Unlocking the bootloader: a must-do step for Fastboot and custom firmware

The bootloader on all Xiaomi smartphones is locked by default. To flash the device through Fastboot or install TWRP, it must be unlocked, a process that erases all data and requires the Mi Account to be linked to the device.

Step-by-step instructions for unlocking

1. Link your Mi Account: Go to Settings → Xiaomi account and log in. Make sure your account has SMS/email verification enabled.
2. Enable USB debugging: Activate Developer Mode (7 times click on the MIUI version in About Phone), then enable USB Debugging and OEM Unlock in Settings → Additional → For Developers.
3. Download Mi Unlock Tool: The official utility is available on the Xiaomi website (you will need a Mi Account).
4. Connect your phone to your PC in Fastboot mode (turn off the device, then press Volume Down + Power).
5. Start unlocking: In Mi Unlock Tool, log in to your account and follow the instructions.The process can take up to 72 hours (due to Xiaomi's validation).

⚠️ Warning: Once the bootloader is unlocked, the smartphone will be reset to factory settings. If you don't backup, all data (including photos in internal memory) will be lost without the ability to recover.

Fastboot firmware: a reliable method for official and custom ROMs

Fastboot is a good way to install official firmware (.tgz) or custom builds if you already have a bootloader unlocked, and it's more reliable than Recovery, because it runs through all parts of the device, including boot and system.

What's the matter?

• 🖥️ PC Windows/Linux and installed Xiaomi drivers (download Mi Flash Tool).
• 📦 Firmware in.tgz (official) or.img (castom) format).
• 🔌 Original. USB-cable (important for stable connection!).

Firmware instructions

1. Unpack the firmware archive into a folder without Cyrillic characters (e.g., C:\ROM\).
2. Turn off your phone and log in to Fastboot (Loudness Down + Power).
3. Connect the device to your PC and start the Mi Flash Tool.
4. In the utility, click Select and specify the path to the folder with the firmware.
5. Select firmware mode: Clean all - complete cleaning (recommended when changing the version of MIUI), Clean all and lock - cleaning + lock bootloader (only for official firmware!), Save user data - data storage (not always stable).

Flash

⚠️ Note: If you are flashing custom build (like LineageOS), never choose Clean all and lock – this will block the bootloader and make it impossible to install unofficial firmware in the future.

Download the official firmware from the Xiaomi website

Install Mi Flash Tool and Drivers

Unlock the bootloader (if not done earlier)

Check the battery power (minimum 60%)

Connect the original USB-cable-->

Installation of custom firmware: TWRP and alternative ROM

If you are not satisfied with the standard MIUI, You can install custom firmware, like Pixel Experience (pure Android) or LineageOS (maximum customization). TWRP — Alternative Recavatories that allow for unofficial ZIP-file.

Step 1: Installation of TWRP

Download the current version of TWRP for your Redmi Note 12 model from twrp.me.

fastboot flash recovery twrp-3.7.0_12-xxx.img


fastboot reboot recovery

Step 2: Firmware custom ROM

1. Download. ZIP-firmware file (e.g, PixelExperience_Plus_redmi_note12-13.0-20231015.zip) and move it to the phone.
2. Sign in to TWRP (Loudness up + Power when the phone is off).
3. Make Wipe → Advanced Wipe and mark Dalvik, Cache, System, Data.
4. Press Install, select. ZIP-Firmware file and confirm installation.
5. After completion, swipe Gapps (if not included in ROM) and Magisk (for root rights).
6. Reboot the device (Reboot System).

Important: The first download of custom firmware can take up to 20 minutes.

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Custom firmware requires regular manual updates, and keep an eye on new releases on the XDA Developers or 4PDA forums to avoid security vulnerabilities.

Solving typical firmware errors

Even when following instructions, you may experience failures, and here are the most common mistakes and ways to correct them:

⚠️ Note: If the Redmi Note 12 is constantly bootlooped after you have firmware, don’t try to flash it again. → Format Data in the TWRP (It will remove everything, including the internal memory!).

FAQ: Frequent questions about the Redmi Note 12 firmware