Fastboot on Xiaomi Redmi 4X: a complete guide to unlock and firmware

Xiaomi Redmi 4X (codenamed santoni) is one of the brand’s most popular budget smartphones, but even years after its release, owners are faced with the need to reflash the device, unlock the bootloader or restore functionality through Fastboot mode. This mode is not just a tool for enthusiasts, but often the only way to bring the phone back to life after a failed update, virus attack or “brick” the system.

Unlike Recovery, where capabilities are limited to standard MIUI features, Fastboot allows you to access low-level commands via PC. Here you can flash customized Recovery (TWRP), unlock the bootloader officially through the Mi Unlock Tool, or even restore the phone if it does not turn on. However, working with Fastboot requires accuracy: one wrong action - and the Redmi 4X will turn into a "brick".

In this guide, we will take you through all the steps from driver preparation to fastboot flash firmware, and how to avoid common mistakes. If you’ve never worked with ADB or Fastboot, don’t worry: the manual is tailored for beginners, but with nuances in mind, it’s for the Redmi 4X.

What is Fastboot and Why You Need It on Redmi 4X?

Fastboot is a protocol for interacting with the Android device loader via USB-Unlike a normal phone, in this mode, the smartphone does not load the operating system, but waits for commands from the user. 4X Fastboot is used for the purpose of:

• 🔓 Unlocking the bootloader (a mandatory step before installing custom firmware or TWRP).
• 📱 Firmware official / custom software through fastboot flash commands.
• 🔄 Phone Recovery After Failures When Recovery Is Unavailable.
• 🛠️ Patch installations (e.g., error correction with sensor or communication module).

It is important to understand: Fastboot on Redmi 4X Not the same as EDL-Mode (Emergency firmware via Qualcomm 9008): the first works at the bootloader level and requires an unlocked bootloader, and the second is the “last frontier” for recovering phones with damaged firmware (but it requires authorized Xiaomi accounts or boxes).

In practice, 90% of tasks are solved through Fastboot, but there is a caveat: Xiaomi blocks the bootloader on all devices by default, which means that before the firmware you will have to go through the unlock procedure through the Mi Unlock Tool – more about this in the next section.

Preparation for work: drivers, tools and unlocking the bootloader

Before you can transfer Redmi 4X to Fastboot, you need to prepare the computer and the device itself, and skipping any of the steps can lead to errors such as waiting for the device or unauthorized.

1. Installation of drivers and ADB/Fastboot

To communicate the phone with the PC will need:

• 🖥️ Xiaomi Drivers: Download Mi PC Suite or install drivers manually via Android SDK.

Attention! On the Redmi 4X, the OEM unlock may disappear after the reboot, which is normal. It is important to turn it on immediately before switching to Fastboot.

2 Unlock the bootloader through the Mi Unlock Tool

Xiaomi requires official unlocking of the bootloader for all manipulations in Fastboot.The process takes up to 720 hours (30 days) of waiting, if the Mi Account is not tied to the device in advance.

1. Download the Mi Unlock Tool and log in to your Xiaomi account.
2. Connect Redmi 4X to your PC in Fastboot mode (see next section).
3. In the program, click Unlock and follow the instructions. If you receive a waiting message, you will have to wait (usually 168 hours for new accounts).

Install Xiaomi | Download platform-tools and unpack |Enable USB debugging and OEM |Link Mi Account to phone | Download Mi Unlock Tool-->

Critical detail: if you reset your phone to factory settings after you have tied your account, the waiting time for unlocking will reset! so link your account before any firmware manipulations.

How to Sign In to Fastboot on Xiaomi Redmi 4X: 3 Working Ways

You can put the Redmi 4X into Fastboot mode even if the phone doesn't turn on, and the main thing is that the battery is at least 30 percent charged.

Method 1: Through buttons (if the phone is turned off)

1. Turn off the phone (press Power + Volume up for 10 seconds).
2. Squeeze the power. + Loud down and hold for 5-7 seconds until the Fastboot logo appears. FASTBOOT).

Method 2: ADB (if the phone is on)

If the phone is working, but you need to go to Fastboot without turning off:

adb reboot bootloader

The command will be executed only if debugging is enabled via USB and the phone is recognized in adb devices.

Method 3: Through Custom Recovery (TWRP)

If Redmi 4X already has TWRP installed, sign in (Power + Volume Up), then select Reboot → Bootloader.

⚠️ If the phone is not detected in fastboot devices after logging in to Fastboot, check:

• 🔌 Cable USB (It is better to use the original from Xiaomi).
• 🖱️ Port port USB on a PC (try it out) USB 2.0 instead of 3.0).
• 🔄 Reinstall drivers in Device Manager (should be displayed as Android Bootloader Interface).

Fastboot Teams for Redmi 4X: What You Can Do

Once you successfully connect Redmi 4X in Fastboot mode, you can use the following commands, all of which are entered in the command prompt (cmd) from the platform-tools folder.

⚠️ Attention: Quickboot Oem unlock on Redmi 4X It doesn't work - unlock is only possible through the Mi Unlock Tool! Also avoid commands like fastboot erase without understanding the consequences - it can erase critical partitions.

For the official firmware MIUI via Fastboot, use the script flash_all.bat From the firmware archive, for example, for Global Stable firmware:

fastboot flash boot boot.img


fastboot flash system system.img




fastboot flash recovery recovery.img




fastboot reboot

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If the firmware is interrupted with the error remote: partition table doesn't exist, then you are trying to flash an incompatible version of MIUI. For Redmi 4X, only firmware codenamed santoni is suitable!

TWRP firmware and custom firmware through Fastboot

Installing TWRP is the first step for those who want custom firmware (LineageOS, Pixel Experience) or root rights. Redmi 4X recommends TWRP version 3.2.3-0 or later (but not all builds support FBE encryption).

Step 1: Download TWRP

The official TWRP version for santoni can be found at twrp.me. Alternative builds (e.g., FBE-enabled) can be found on the 4PDA or XDA forums.

Step 2: TWRP firmware

1. Place the twrp-3.2.3-0-santoni.img file in the platform-tools folder.
2. Connect Redmi 4X in Fastboot mode.
3. Run the command: fastboot flash recovery twrp-3.2.3-0-santoni.img
4. Immediately after the firmware, go to TWRP, otherwise the standard MIUI will overplay it: fastboot boot twrp-3.2.3-0-santoni.img

Important: After the first download to TWRP, be sure to back up the EFS partition (responsible for IMEI)! This will save you from losing the network in unsuccessful experiments.

Step 3: Custom firmware firmware

You can install any firmware in.zip format through TWRP. Popular options for Redmi 4X:

• 📱 LineageOS 16/17.1 (Android 9/10)
• 🎨 Pixel Experience (Pure Android with Google chips)
• ⚡ MIUI Pro (modified) MIUI publicity)

⚠️ Attention, before the custom firmware:

1. Make sure the firmware is compatible with santoni.
2. Make a full backup in TWRP (including Boot, System, Data).
3. Format Data (if you move from data to data) MIUI on AOSP-firmware).

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Custom firmware erases all data! Backing up through TWRP or Mi Cloud is a must.

Typical errors and their solutions

Fastboot on Redmi 4X is often accompanied by errors, and let’s look at the most common and ways to fix them:

If Redmi 4X is not turned on after the firmware is installed (black screen, vibration without image), try:

1. Press Power + Volume up for 20 seconds (hardware reset).
2. Connect to your PC and check if the device is detected in fastboot devices.
3. Swipe the official MIUI through the Mi Flash Tool (select the clean all option).

FAQ: Frequent questions about Fastboot on Redmi 4X