How to flash Xiaomi Redmi 4X through Fastboot: a complete guide with unlocking and choosing firmware

Why is Fastboot the best way to run Redmi 4X?

Fastboot is a method that allows you to install official or custom firmware directly through your computer, bypassing the limitations of the standard recovery mode. For Xiaomi Redmi 4X (codename santoni), this method is especially relevant if the device is locked, unstable or requires a rollback to the previous version of MIUI. Unlike the update via Ota Updater, Fastboot gives you full control over the process, but requires unlocking the bootloader and preparing the PC.

The main advantages of the method are: (1) Ability to install any version of MIUI (including global, Chinese or EEA). (2) Recovery of the brick (defunct device) when the firmware fails. (3) Clean installation without residues from the previous system.

However, there are risks: if you miss commands or interrupt the process, Redmi 4X can turn into a brick, so it is important to follow the instructions without improvisation.

This article is suitable for both beginners and experienced users.

✅ Preparation of drivers and tools on PC.

✅ Unlock the bootloader through the official service Xiaomi.

✅ Finding and Choosing the Right Firmware for Santoni.

✅ Step-by-step installation through MiFlash and alternative tools.

✅ Common Errors and Solutions (from Anti-Rollback to Driver Problems).

Preparation: what you need to firmware through Fastboot

Before you start, make sure you have everything you need, and without proper preparation, the firmware can fail or damage the system.

• 📱 Smartphone: Xiaomi Redmi 4X (santoni model with a battery charge of at least 60%, with a low charge, the device can shut down during the process.
• 💻 Computer: Windows 7/10/11 (64-bit MacOS or Linux will require additional settings.
• 🔌 Cable USB: Original or high quality (cheap cables can interrupt the connection).
• 🔧 Drivers: Mi USB Driver for device recognition in Fastboot mode.
• 📁 Firmware: official.tgz or.zip file for santoni (download only from the official Xiaomi website).
• 🛠️ Tools: MiFlash (for Windows) or fastboot from Android SDK.
• 🔑 Mi Account: Linked to the device (required to unlock the bootloader).

Pay special attention to the firmware versions. For the Redmi 4X, there are:

Global Stable – for the international market.

China Stable – with Chinese-enabled services.

EEA (European) – no Chinese apps, but with Google Play support.

Developer – test builds with new features (may contain bugs).

⚠️ Attention: If your Redmi is 4X It was purchased in China, and the firmware of the global version can block the network due to differences in modem!

Unlock the bootloader on Redmi 4X: the official way

Without unlocking the bootloader, it is impossible to flash Redmi 4X through Fastboot. Xiaomi blocks this process to protect against unauthorized changes, but provides an official way to unlock through the Mi Unlock tool.

Step 1: Linking your Mi Account to your device

1. Go to Settings → About Phone → MIUI version and tap 7 times to activate Developer Mode.
2. Back to Settings → Additionally. → For developers and include: 🔓 OEM-Unlocking (may be absent on some versions) MIUI). 🔌 Debugging by USB.

Mi

Settings → Mi Account → Synchronization

Mi Unlock

Step 2: Request Unlocking through Mi Unlock

1. Download the Mi Unlock Tool and install it on PC.
2. Start the program, log in to your Mi Account (should match the one on your phone!).
3. Put Redmi 4X into Fastboot mode: turn off the device, then press Volume down + Power until the bunny appears in the eardrum cap.
4. Connect your phone to your PC. Mi Unlock will have a message about a successful connection.
5. Press Unlock and wait until it is completed (usually takes 3-5 minutes).

Once unlocked, the device will automatically reset to factory settings!

⚠️ Warning: If Mi Unlock shows a "Couldn't unlock" error or requires you to wait 72/168/360 The clock is the standard delay from Xiaomi for new accounts. Connect to the Internet on your phone and wait for the specified time, periodically repeating the attempt.

Selecting firmware for Redmi 4X: official vs custom

The firmware choice depends on the stability of the Redmi 4X after installation. Official builds from Xiaomi guarantee compatibility with hardware, but may contain unnecessary applications. Custom ROMs (such as LineageOS or Pixel Experience) offer a “pure” Android, but require additional knowledge.

For most users, the best choice is the official global stable firmware. It has been tested on Redmi 4X and contains all the necessary drivers. If you want the latest version of Android, look at Xiaomi.EU (unofficial MIUI builds with Google Play support and without Chinese restrictions).

Critical information: The firmware for Redmi 4X (santoni) is not compatible with Redmi 4/4A/4 Prime! Installing the wrong version will result in a "brick." Always check the device's code name in the settings or through the fastboot getvar product command.

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Before downloading the firmware, check its version on the Xiaomi Firmware Updater website - the latest builds with angelogs are published there.

Step-by-step: Redmi 4X firmware via MiFlash

Now, to the firmware process itself, we're going to use MiFlash, the official tool from Xiaomi, which automates the firmware installation in Fastboot mode.

Step 1: Install MiFlash and Drivers

1. Download MiFlash and install it on PC.
2. Unpack the archive with firmware (should be a file) flash_all.bat and folder images).
3. Install the drivers: 🖥️ For Windows: Download MiPhone Driver and run DriverInstall.exe. 🐧 For Linux: Add udev rules (instructions here).

Step 2: Preparing the phone

1. Turn off the Redmi 4X.
2. Press Volume Down + Power to enter Fastboot (screen with a bunny).
3. Connect your phone to your PC. Android Bootloader Interface should appear in Device Manager.

Step 3: Firmware through MiFlash

1. Run MiFlash on behalf of the administrator.
2. Click Select and point the way to the folder with unpacked firmware.
3. At the bottom of the window, select the firmware mode: 🔄 Clean all – complete cleaning (recommended). 🔄 Clean all and lock - cleaning + Loader lock (only for official firmware!). 🔄 Save user data – saving user data (risky, may cause errors).

Refresh

Flash

Once the firmware is successful, Redmi 4X will automatically restart. The first onset can take up to 15 minutes - don't interrupt the process!

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Always use clean all mode when changing MIUI (e.g. from Global to China) to prevent system file conflicts.

Common mistakes and their solutions

Even with the correct following of the instructions, errors can occur, and here are the most common problems and ways to fix them:

• 🚨 anti-rollback (error) 7/8 MiFlash: Reason: Trying to install an older version MIUI, Xiaomi blocks rollbacks to older builds because of changes in the bootloader. Solution: run a newer version or the same one that was there before. Check the current firmware version in Settings. → The phone. → Version. MIUI.
• 🚨 This package is for "santoni" devices; this is a": Reason: You didn't download the firmware for Redmi 4X (For example, Redmi 4 Pro or Redmi Note 4X). Solution: Download the right firmware for the santoni model.
• 🚨 Device not defined in MiFlash: Reasons: Drivers not installed. Cable or port USB Antivirus blocks MiFlash. Solution: check Device Manager, try another cable/port, disable antivirus.
• 🚨 After the firmware, there's no network (IMEI Lost): Cause: modem partition damage or incompatible firmware (e.g., Chinese on a global device). Solution: run the correct version MIUI or restore IMEI through QCN-File (requires an engineering menu).

⚠️ Note: If you have been running Redmi 4X getting stuck on the Mi logo or rebooting in an infinite loop, try: Reset settings via Recovery (Loudness up) + Nutrition → Repeat the firmware with clean all mode. Install another version MIUI (For example, instead of trying to get a global EEA).

Alternative Firmware Methods: Without MiFlash

If MiFlash doesn’t work or you prefer more control, you can flash Redmi 4X through the command line using fastboot from Android SDK. This method requires knowledge of commands, but gives flexibility (for example, allows you to flash individual partitions).

Step 1: Install ADB and Fastboot

1. Download Google’s Platform Tools and unpack it into any folder.
2. Open Command Prompt in this folder (press Shift + PCM → Open the command window).

Step 2: Checking the connection

Enter the command:

fastboot devices

If the device is determined (its serial number appears), you can continue.

Step 3: Firmware by command

Go to the folder with unpacked firmware and do:

fastboot flash boot boot.img


fastboot flash recovery recovery.img




fastboot flash system system.img




fastboot flash vendor vendor.img




fastboot flash modem NON-HLOS.bin




fastboot flash fsg fsg.mbn




fastboot erase userdata




fastboot erase cache




fastboot reboot

This is a great way to use it for power users, and if you're not sure about commands, you'd better use MiFlash.

@echo off


fastboot flash boot boot.img




fastboot flash recovery recovery.img




...




fastboot reboot

-->

What to do after firmware: setup and optimization

After a successful firmware Redmi 4X will require initial configuration.

• 🔄 Reset to factory settings (if you didn't clean all): Go to Settings → Additionally. → Recovery and discharge → Resetting settings. This will help avoid conflicts between old and new files.
• 🔒 Blocking the bootloader (optional): If you have installed the official firmware and do not plan further experiments, you can block the bootloader with the command: fastboot oem lock ⚠️ Then I'll do a custom. ROM It will be impossible to roll back to another version without re-unblocking!
• 📱 Setting up region and language: If you have stitched the Chinese version, switch the region to India or Russia in Settings → Additionally. → Region to avoid restrictions.
• 🚀 Performance Optimization: Turn off animation and background processes in Settings → For developers: Animation of windows → Off. Process limit → Standard limit

It is also recommended that:

• 🔋 Calibrate the battery: fully discharge and charge the phone 2-3 successively.
• 🛡️ Install security updates in Settings → The phone. → Updating the system.
• 📲 Set up Google Play (if you have a global or EEA version).

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If you have lags after you have firmware, try disabling MIUI Optimization in the developer settings, which will speed up the interface, but may disrupt some features (such as themes).

FAQ: Frequent questions about Redmi firmware 4X