How to reflash Xiaomi Redmi 4X: official and custom methods

Xiaomi Redmi 4X (codenamed santoni) remains a popular budget smartphone even years after its release. However, over time, users face slowdowns, lack of security updates or the desire to install custom firmware like LineageOS or Pixel Experience. Flashing the device can solve these problems, but requires care: an error in the stage of unlocking the bootloader or choosing the wrong version of software can turn the phone into a “brick”.

In this guide, we will analyze all the current ways to flash the Redmi 4X in 2026: from the official update via MIUI Updater to install custom software via TWRP or Fastboot. Particular attention will be paid to preparing the device, unlocking the bootloader (without it custom firmware can not be installed), and the typical errors that beginners make. If you have never flashed a smartphone before, start with the official method, since it is the most secure.

Preparation for Flashing: What to Do Before Starting

Before you start firmware, make sure that all the mandatory conditions are met. Neglecting them can lead to data loss, device malfunction or complete inoperability.

• 🔋 Battery charge at least 60 percent. The firmware process can take up to 30 minutes, and the battery will be discharged at that point, interrupting the operation.
• 📱 Backup all important data (photos, contacts, messages) Use Mi Cloud, Google Drive or local copying on your PC!
• 🖥️ Windows computer 10/11 (for the Fastboot methods and TWRP). MacOS or Linux may have driver problems.
• 🔌 Original. USB-Cheap cables often don't transmit data correctly, leading to firmware errors.

Also check the current version. MIUI And the device model. Go to Settings for that. → On the phone, in the line "Version" MIUI» You'll see something like this. V12.5.3.0.RDFCNXM, and in "Device Model" - Redmi 4X It's not like the global firmware (Global) is not good for China, and vice versa, and it's going to lead to an anti-rollback error»!

Make a data backup|Charge the phone to 60%+|Install Xiaomi drivers on PC|Download the correct version of the firmware|Disable the antivirus (it can block firmware files)-->

Official firmware through MIUI Updater: the most secure method

If your goal is to simply upgrade Redmi 4X to the latest MIUI without risk, use the built-in MIUI Updater, which does not require unlocking the bootloader and is suitable even for beginners, but it only works for official firmware - custom software (such as LineageOS) can not be installed this way.

Instructions:

1. Open the Update app (the icon with the arrow up) on your phone.
2. Click on the three dots in the top right corner and select Select Service Pack.
3. Specify the path to the downloaded firmware file (.zip format). 4X Look for files with a type name miui_HM4XGlobal_V12.5.3.0.RDFCNXM_....
4. Confirm the installation and wait for the process to be completed (the phone will restart several times).

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

• 🔄 Rename the firmware file to update.zip try again.
• 📁 Move the file to the root of internal memory (not to folders!).
• 🔌 Connect your phone to charge during the update.

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If MIUI Updater does not see the downloaded firmware file, check its integrity through an archiver (e.g., 7-Zip).

Unlocking the bootloader: a mandatory step for custom firmware

Without unlocking the bootloader, you can't install TWRP, LineageOS, or any other unofficial firmware. Xiaomi locks the bootloader on all devices by default, and unlocking it requires confirmation through your Mi Account. Important: once unlocked, all data on the phone will be erased!

Step-by-step:

1. Link Mi Account to your phone: Settings → Xiaomi Account → Add an account.
2. Activate USB debugging: Settings → About Phone → MIUI version (click 7 times until the message “You’re a developer” appears). Then go back to Settings → Additional → Developer and enable USB Debugging and OEM Unlock.
3. Download Mi Unlock Tool (the official utility from Xiaomi) and install it on PC.
4. Launch the utility, log into your Mi Account and connect your phone in Fastboot mode (turn off the phone, then press Volume Down + Power before a bunny with the word Fastboot appears).
5. Click Unlock in the program and wait until it is completed (usually takes 5-10 minutes).

Once successfully unlocked, the bootloader will remain unlocked even after flashing it again, however, Xiaomi can block it when installing the official firmware via Fastboot (but not through Recovery).

Installation of custom firmware through TWRP

If you want to install LineageOS, Pixel Experience or other custom firmware, you need TWRP Recovery, an alternative recovery menu that allows you to install unofficial software, backup and restore the system.

Instructions for installing TWRP and custom firmware:

1. Download the latest version of TWRP for Redmi 4X (file with.img extension).
2. Download the firmware itself (e.g. LineageOS 18.1 for santoni) and the GApps package (Google services if needed).
3. Move firmware and GApps files to your phone or SD-map.
4. Reboot your phone to Fastboot mode and connect to your PC.
5. Open the command line in the folder with fastboot and type: fastboot flash recovery twrp-3.7.0_9-0-santoni.img fastboot boot twrp-3.7.0_9-0-santoni.img That'll set it up. TWRP And he'll load the phone right into it.
6. In TWRP, run Wipe → Advanced Wipe and mark Dalvik, Cache, System, Data. Then swipe to reset.
7. Go back to the main menu, select Install, and specify the path to the firmware file. After installing it, repeat the step for GApps.
8. Reboot your phone: Reboot → System.

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Never install firmware for another model (e.g. Redmi 4/4A/4 Prime)! this will cause the communication module, camera or full bricks of the phone to fail.

The first boot after installing custom firmware can take up to 15 minutes. If the screen does not respond for more than 20 minutes, then something has gone wrong (possibly incompatible with the version of the bootloader).

Fastboot Firmware: for official and custom software

The Fastboot method is suitable for both official firmware installation (if MIUI Updater doesn't work) and some custom builds, and the main advantage is reliability, since the firmware runs directly through the PC, but this method erases all data and requires an unlocked bootloader.

Step-by-step:

1. Download the official firmware for Redmi 4X in.tgz format (for Fastboot). Unpack the archive in a folder on your PC.
2. Install ADB and Fastboot drivers (or use the Mi Flash Tool).
3. Transfer the phone to Fastboot mode (clip Volume down + Power when the phone is off).
4. Connect the phone to the PC and open the command line in the firmware folder.
5. Enter the command to check the connection: fastboot devices If the device is determined (the serial number will appear), continue.
6. For official firmware, use the Mi Flash Tool: Select a folder with the unpacked firmware. Specify Clean all mode. Press Flash and wait until it's finished.

LineageOS

fastboot flash boot boot.img


fastboot flash recovery twrp.img




fastboot flash system system.img




fastboot wipe userdata




fastboot reboot

If the Mi Flash Tool is 0x80070026, try:

• 🔌 Connect the phone to another USB-port (preferably) USB 2.0).
• 🖥️ Launch the program on behalf of the administrator.
• 🔄 Reinstall Xiaomi drivers manually through Device Manager.

Common Mistakes and How to Avoid Them

Even experienced users sometimes experience problems with the Redmi 4X firmware, and here are the most common bugs and ways to solve them:

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If it's gone after the firmware. IMEI, Restore it with the help of a tool SN Write Tool (requires an authorized Xiaomi account). 4PDA or XDA.

Another common problem is hanging on the MI logo after installing custom firmware.

• 🔄 Incompatibility of the firmware core with the loader version.
• 📁 No file. vendor.img (mandatory for Android 8+).
• 🔧 Incorrect Wipe before installation (System, Data, Cache must be cleaned).

How to return the official firmware if something went wrong

If after experiments with custom firmware, the phone began to work unstable or does not turn on at all, you can return the official MIUI.

Instructions for returning to stock firmware:

1. Download the official firmware for Redmi 4X in Fastboot format (.tgz).
2. Unpack the archive in a folder on your PC.
3. Put your phone in Fastboot mode (if it doesn’t turn on, press Volume Down + Power on the device turned off).
4. Start the Mi Flash Tool, select the folder with the firmware.
5. At the bottom of the program, select Clean all mode (if you want to save data – Clean all and lock, but this will block the bootloader again).
6. Press Flash and wait until it is completed (usually 5-10 minutes).

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If after returning to the official firmware, the phone requires authorization to Mi Account, and you do not remember it, use the Mi Account Unlock Tool (free on the forums).

After successful firmware, the phone will reboot to standard MIUI, and if you want to re-install custom software, you'll have to re-unblock the bootloader.

FAQ: Answers to Frequent Questions