How to Reflash Xiaomi Redmi 12: Official and Unofficial Methods

Xiaomi Redmi 12 may need to be flashed to install a new version of MIUI, remove bloat, improve performance, or even restore a brick. But the process requires care: the wrong actions will lead to data loss, device lock or hardware failure. In this guide, we will analyze all the current ways, from official updates through MIUI Updater to manual firmware through Fastboot and TWRP, taking into account the features of the Redmi 12 model (codename sky).

It’s important to understand that Redmi 12 came with different firmware versions for the global (Global), Chinese (China), European (EEA) and Indian (India) markets. Installing incompatible firmware can block the network or IMEI. Also consider that since 2023, Xiaomi has tightened its bootloader unlock policy – now it requires binding Mi Account account and waiting up to 720 hours (30 days).

1. Preparation for flashing: what to do before the start

Before you start firmware, follow the mandatory steps, and skipping any of them can make it impossible to restore the device through standard Xiaomi tools.

• 🔋 Charge the battery to at least 60%. When discharged during firmware through Fastboot, the phone can turn into a brick».
• 📱 Make a backup copy through Settings → The phone. → Backup or Mi Cloud. This will save contacts, SMS Settings, but not system applications.
• 🔑 Check the status of the bootloader: if it is locked, it will take up to 30 days to unlock the status).
• 💻 Install drivers: for Windows, download Mi Flash Tool (includes drivers), for Linux/macOS — Check for adb and fastboot via the terminal.

Pay special attention to the choice of firmware. Redmi 12 only suits files marked with sky in the title.

• 🌍 Official website MIUI — for stable and beta versions.
• 🔧 Xiaomi Firmware Updater – a firmware archive with update history.
• ⚠️ Avoid third-party resources such as 4PDA hash-free (MD5 or SHA256). Fake firmware may contain malicious code.

⚠️ Note: If your Redmi 12 is purchased in China (China version), the firmware of the global version of Global will block access to Google Services.

2. Method 1: Update via MIUI Updater (without unlocking)

The safest method is to update through the built-in System Update app, which is suitable for installing official firmware without loss of data and does not require unlocking the bootloader, but only works if:

• 📱 The phone is on and loaded into the system.
• 🔄 Update available for your current version MIUI.
• 📶 There is a stable connection to Wi-Fi (load volume up to 3 GB).

Instructions:

1. Open Settings → About the phone → System update.
2. Click on the icon «⋮» (three dots) in the upper right corner and select Select Service Package.
3. Specify the path to the downloaded firmware file (.zip format).
4. Confirm the installation and wait for the restart (it will take 5-15 minutes).

If the update is “hanging” during the verification phase, try:

• 🔄 Rename the firmware file to update.zip try again.
• 📁 Put the file in the root of internal memory (not in folders).
• 🔋 Connect the charger (sometimes the system requires 100% charge).

⚠️ Note: If after the update the phone is fixated on the logo MI, Reset via Recovery: Press the Power + Volume Up, select Wipe data → Reboot.

Method 2: Fastboot Firmware (official method)

Fastboot is used to install official firmware when you can’t boot into the system (for example, after a failed update), it requires an unlocked bootloader and a PC with Mi Flash Tool or Platform Tools installed.

Step-by-step:

1. Download the firmware in.tgz format (for example, sky_global_images_V14.0.1.0.TMBMIXM_20231010.0000.00_12.0_global_1234567890.tgz) and unpack it.
2. Turn off your phone and press Power + Volume Down to enter the Fastboot (a screen with a rabbit in a hat-eared).
3. Connect the device to your PC and check for detection by command: fastboot devices must display a serial number.
4. Launch the Mi Flash Tool, select the folder with the unpacked firmware and press Refresh → Flash.
5. Select Clean All (Full Cleaning) or Clean All and Lock (Cleaning + Lock bootloader).

It takes 5-10 minutes. When it's done, the phone automatically restarts. If the Mi Flash Tool gives you a critical partition flashing error, it's not allowed, it means:

• 🔓 The bootloader is blocked – unlocking is required.
• 📁 Selected firmware for another model (check the sky code).
• 🔧 Uses an outdated version of the Mi Flash Tool (download the latest from the official website).

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If the Mi Flash Tool doesn’t see the device, try connecting the phone to another device. USB-port (preferably) USB 2.0) or use the original Xiaomi cable. Also check if debugging is enabled USB in the developer settings (Settings) → The phone. → Version. MIUI — press 7 times).

Method 3: Install custom firmware via TWRP

For enthusiasts who want to install LineageOS, Pixel Experience or xiaomi.eu, you will need custom TWRP recavers. This method gives full control of the system, but deprives official support and can lead to problems with Widevine L1 (lower streaming quality on Netflix/Disney+).

Instructions:

1. Unlock the loader (required!).
2. Download. TWRP for Redmi 12 (file twrp-3.7.0_12-sky.img).
3. Fastboot: Fastboot Flash Recovery twrp-3.7.0_12-sky.img fastboot reboot recovery
4. In TWRP, run Wipe → Format Data (enter yes), then copy the firmware to your phone and install it through Install.

The most popular custom firmware for Redmi 12:

• 📱 xiaomi.eu — MIUI without Chinese Bloat, with Google Services.
• 🤖 LineageOS – pure Android without branded shells.
• 🎮 Pixel Experience – Android with Google Pixel chips.

⚠️ Note: After installing custom firmware, Banking may stop working API (Payment via SberPay, Tinkoff, etc. Solved by Magisk and Universal SafetyNet Fix.

5. Unlocking the bootloader: a step-by-step guide

Without unlocking the bootloader, you can't flash custom recavers or unofficial firmware. The process takes up to 30 days and requires a Mi Account to be tied to the device.

Algorithm of action:

1. Link Mi Account in your phone settings (Settings → Accounts → Mi Account).
2. Activate debugging over USB (Settings → About Phone → MIUI version – press 7 times, then go back to Additional → For Developers).
3. Download the Mi Unlock Tool and log in.
4. Connect your phone in Fastboot mode and press Unlock. If you have a waiting message, wait. SMS-notification (usually 168-720 hours).

After unlocking:

• ✅ The bootloader will remain unlocked even after resetting.
• ⚠️ Xiaomi warranty is canceled (but you can block the bootloader back through fastboot oem lock).
• 🔒 Some features (such as Mi Pay) may stop working.

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Unlocking the bootloader is an irreversible process unless you lock it back, and once unlocked, the phone becomes vulnerable to malware as the firmware signature check is turned off.

6. Solving common errors after firmware

Even with a successful firmware, there can be problems, and here are the typical scenarios and ways to fix them:

If the sound is lost or the sensor is not working after firmware, check:

• 🔊 Correct firmware installation (possibly missed Wipe step) Dalvik/Cache into TWRP).
• 📱 Compatibility of firmware with hardware platform version (Redmi 12 has modifications with different chips: Helio) G88 Helio G85).
• 🔧 Root rights (some firmware requires Magisk to operate modules correctly).

7.How to return the official firmware after custom

If the custom firmware experiments are unsuccessful, you can return the stock MIUI.

1. Download the official firmware in.tgz format for your model.
2. Unpack it and find the file. flash_all_lock.bat (for Windows or flash_all_lock.sh (for Linux/macOS).
3. Run the script - it will sew the stock firmware and block the bootloader.

Important:

• 🔒 After blocking the bootloader, installing custom firmware will be impossible without re-unblocking.
• 📱 All data will be erased (including internal memory).
• 🔧 If your phone is not loading, use the Mi Flash Tool in Clean All and Lock mode.

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Before you go back to stock firmware, back up the persist partition in TWRP. This will keep the sensors and IMEI calibrated if something goes wrong.

FAQ: Frequent questions about Redmi firmware 12