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

The Xiaomi Redmi 4X (codenamed santoni) remains a popular budget smartphone years after its release. However, over time, its performance declines and official updates stop coming out. The phone’s firmware can give it a second life: speed up work, add new features or even install the current version of Android. But the process has nuances, from unlocking the bootloader to choosing the right version of software.

In this article, we will discuss all the current ways to update Redmi 4X in 2026: through a regular update (MIUI Updater), manual installation in Recovery and deep firmware through Fastboot. Separately, we will focus on preparing the device, unlocking the bootloader and solving typical errors. If you are a beginner, start with the official methods. For experienced users, instructions for installing custom firmware like LineageOS or Pixel Experience.

⚠️ Important: Smartphone firmware is always fraught with risks, improper actions can lead to a "brick" (complete failure) of the device, all manipulations you perform at your own risk. 4X — your main phone, prepare a data backup and an alternative device for communication in advance.

1.Preparation of the phone for firmware

There are several critical steps to follow before any firmware is run, and skipping at least one of them can cause a process to crash or data to be lost.

First, check the current version of MIUI and the status of the bootloader.

1. Go to Settings. → The phone.
2. Tap 7 times on the MIUI version to activate Developer Mode.
3. Back to Settings → Additionally. → For developers.
4. Find the Mi Unlock Status item – if it says Locked, the bootloader will have to unlock.

Second, back up all the data, and the firmware (especially through Fastboot) erases the phone's internal memory.

• 📱 Local Copying: Transfer photos, videos and documents to a computer or external drive.
• ☁️ Cloud Services: sync contacts, notes and apps through Mi Account, Google or third-party clouds.
• 🔄 Backup of settings: in Settings → Additionally. → Backup save system settings.

Third, charge your phone to at least 60 percent, and if you interrupt the firmware because of battery failure, you're almost guaranteed to get a "brick."

• 🔌 Cable USB Type-C (preferably original or certified).
• 💻 Windows computer 7/10/11 (for the Fastboot method).
• 📥 Internet access for downloading firmware and drivers.

Battery charge > 60% | Data backup | Xiaomi drivers installed on PC| Downloaded the desired firmware version | Antivirus disabled (can block firmware files)

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2 Unlock the bootloader on the Redmi 4X

Xiaomi's official firmware via Recovery or MIUI Updater can be installed without unlocking the bootloader. But for custom firmware or firmware via Fastboot, this step is mandatory. The process takes up to 72 hours due to Xiaomi's policy.

Instructions for unlocking:

1. Download the Mi Unlock Tool (official website).
2. Sign in to it under the same Mi Account that is tied to the phone.
3. Put Redmi 4X into Fastboot mode: Turn off the phone, then press Volume down + Power before the hare appears in the eardress cap.
4. Connect your phone to your PC and run the Mi Unlock Tool.
5. Press Unlock and wait until the process is complete. If you have a message saying you need to wait, wait until the time is specified (usually 72 hours) and try again.

⚠️ Note: Once the bootloader is unlocked, all data, including files in internal memory, will be deleted from the phone, and some features (such as Find Device or Mi Pay) may stop working.

If the utility gives you a "Couldn't unlock" error, check:

• 🔗 Is Mi Account Linked to Phone (Settings) → Xiaomi account).
• 🕒 Is it 72 hours since the first attempt to unlock.
• 🔌 Is the phone connected to the front port? USB 2.0 (USB 3.0 can cause problems).

3.Redmi 4X firmware methods: which one to choose?

There are three main methods of firmware Xiaomi Redmi 4X, each of which is suitable for different purposes.

For most users, the best option is firmware through Recovery, which allows you to install the official version of MIUI without unlocking the bootloader, but with complete data cleaning. The Fastboot method is suitable for advanced users who want to install custom firmware (for example, LineageOS 16 for Redmi 4X) or restore the phone after a serious crash.

If your goal is to upgrade to the latest version MIUI, Start by checking availability OTA-update:

1. Go to Settings → About the phone → System update.
2. Click on the three dots in the top right corner and select Select Service Pack.
3. If an update is available, download it and follow the instructions on the screen.

Through MIUI Updater (OTA)| Through Recovery| Through Fastboot| I haven't decided yet

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4. Firmware through Recovery: step-by-step instructions

This method is suitable for installing the official MIUI firmware without unlocking the bootloader. It is useful if the phone is unstable, or you want to return the stock firmware after unsuccessful experiments.

Steps for firmware through Recovery:

1. Download the firmware for Redmi 4X (codename santoni from the official website: 🌐 Download page MIUI. Choose a Redmi model 4X and the correct version (e.g, MIUI 12.5. MIUI 11. Download the file with the.zip extension (not.tgz is for Fastboot).
2. Transfer the firmware to your phone: Connect the Redmi 4X to your computer and copy the downloaded.zip file to the root of internal memory (not to folders!).
3. Start Recovery Mode: Press Volume Up + Power and hold until the Mi logo appears. Release buttons when the Recovery menu appears (in English or Chinese).
4. Reset and install: Select Wipe Data → Wipe All Data (this will delete all data!). Go back to the main menu and select Install update.zip to System. Confirm installation and wait for completion (5-10 minutes).
5. Reboot your phone: Select Reboot → Reboot to System. The first run can take up to 15 minutes - don't interrupt the process!

⚠️ Note: If the phone is stuck on the Mi logo for more than 20 minutes after the firmware is installed, it means that the firmware was chosen incorrectly or the file is corrupted).

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5. Firmware through Fastboot: for power users

Fastboot is the most powerful, but also the riskiest method, which allows you to flash your phone even in case of serious failures when Recovery is not available, and it is also a must for installing custom firmware (for example, LineageOS or Havoc-OS).

Critically, the firmware via Fastboot erases all data on the phone, including internal memory, and requires an unlocked bootloader (see section 2).

Step-by-step:

1. Download the necessary files: 📥 Firmware in.tgz format for Fastboot (official from the Xiaomi website or custom from the forum) XDA Developers). 🖥️ The Mi Flash Tool (you can download it here). 🔧 Xiaomi drivers USB Drivers (unless installed).
2. Prepare the firmware: Uncamp the downloaded.tgz file into a folder on your computer (for example, C:\santoni_fastboot). There's gotta be a file inside. flash_all.bat (for official firmware) or flash_all_except_storage.bat (If you don’t want to erase your internal memory).
3. Put the phone into Fastboot mode: Turn off Redmi 4X. Press Volume Down + Power and hold until the screen with the hare in the eardress cap appears.
4. Sweep your phone: Connect your phone to your PC. Launch the Mi Flash Tool and press Select, then select the folder with the unpacked firmware. At the bottom, select Clean all mode or Clean all and lock mode. + Press Flash and wait until it is completed (the process will take 5-15 minutes).
5. Reboot the device: After the green tick appears in the Mi Flash Tool, disconnect the phone from the PC. Press the power for 10-15 seconds for a forced reboot.

If the phone does not turn on after firmware or hung on the logo, try:

• 🔄 Repeat the firmware with another cable/port USB.
• 📥 Download the firmware again (possibly the file was corrupted when downloading).
• 🛠️ Switch the phone in mode EDL (You need an authorized Xiaomi account and a special cable).

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6. Install custom firmware (LineageOS, Pixel Experience)

If you are not satisfied with standard MIUI, you can install alternative firmware based on Android, for example:

• 📱 LineageOS – “clean” Android without unnecessary applications.
• 🎨 Pixel Experience – firmware with the interface and features of Google Pixel.
• ⚡ Havoc-OS - customizable firmware with many settings.

To install custom firmware will require:

1. Unlocked boot loader (see section 2).
2. Installed custom Recovery (e.g. TWRP)
3. The firmware is.zip compatible with Redmi 4X (santoni).
4. Additionally, GApps (Google Services Package) and Magisk (Root Rights) are available.

Instructions for installing TWRP and custom firmware:

1. Install. TWRP: fastboot flash recovery twrp-3.7.0_santoni.img fastboot boot twrp-3.7.0_santoni.img (Download TWRP for Redmi 4X here.)
2. Make a backup in TWRP: In the Backup menu, select the Boot, System, Data sections and back up to SD-map.
3. Sweat custom firmware: Copy your firmware, GApps, and Magisk files to your phone. In TWRP, select Wipe → Advanced Wipe and tick Dalvik, Cache, System, Data. Go back to the main menu, press Install and select the firmware file. After installing the firmware, repeat the step for GApps and Magisk (if you need root rights).
4. Reboot your phone: Select Reboot → System. The first run can take up to 20 minutes.

⚠️ Note: custom firmware may contain bugs, especially on older devices like Redmi. 4X. Before installing, check the reviews on the forum XDA Developers about the stability of a particular build. Also note that some features (like VoLTE or Wi-Fi Calling) may not work.

7. Solving typical firmware errors

Even if you follow the instructions, you can make mistakes, and let's look at the most common ones and how to fix them.

If after the firmware through Fastboot the phone does not turn on and does not respond to buttons, try:

1. Press Volume Up + Power for 20-30 seconds (forced reset).
2. Connect your phone to charging for 1-2 hours – sometimes “waking up” through charging helps.
3. Swipe your phone in EDL mode (requires an authorized Xiaomi account and a special cable).

If none of the methods worked, the hardware (e.g. flash memory) may have been damaged, and repairs at the service center will be required.

8. Frequently Asked Questions (FAQ)