Reflashing Xiaomi Redmi 4X: official and custom firmware

The Xiaomi Redmi 4X (codenamed santoni) remains a popular budget smartphone years after its release, and owners often face the need to reflash the device — whether it’s to upgrade an outdated MIUI, install custom firmware like LineageOS or Pixel Experience, or bring the phone back to life after a software failure.

In this article, you will find the most current ways to flash Redmi 4X in 2026, including official and informal methods, how to prepare a device, where to download proven firmware, how to unlock a bootloader without risking blocking a Mi Account account, and also look at typical errors and their solutions, especially focusing on data security – how to save photos, contacts and applications before firmware.

Preparation for Flashing: What to Do Before Starting

Flashing is a process that can both revitalize your Redmi 4X and turn it into a brick if you approach it unprepared. The first thing you need to do is back up all the data. Even if you plan to upgrade without resetting, there is always a risk of losing information.

Use standard MIUI tools (Settings → Additional → Backup and Reset) or third-party utilities like Titanium Backup (requires root).

• 📱 Contacts (export to VCF- file or sync with Google)
• 📷 Photos and videos (copy to PC or cloud)
• 🔑 SMS and call log (applications like SMS Backup & Restore)
• 🎮 Game Save (use cloud services or root managers)

Next, check the current firmware version and the status of the bootloader.

1. Open Settings → About Phone → MIUI version and write down the build number.
2. Turn off the phone, then press Volume Down + Power to log into Fastboot Mode.
3. Connect the device to the PC and enter the command: fastboot oem device-info If you see Device unlocked: true in the answer - the bootloader is already unlocked.

⚠️ Warning: If you receive a FAILED error (remote: unknown command) in response to a fastboot oem device-info command, this means that your Redmi 4X has a firmware installed with blocked access to OEM- commands. In this case, you will need to first flash Global Stable ROM through the Mi Flash Tool.

Unlocking the bootloader on the Redmi 4X in 2026

Without the unlocked bootloader, you can flash only official firmware through the Mi Flash Tool. To install custom recavators (TWRP) or alternative firmware (LineageOS, Havoc-OS), unlocking is mandatory. The process has changed since 2020 - now Xiaomi requires a binding Mi Account to the device and waiting 168 hours (7 days) for new accounts.

Instructions for unlocking:

1. Connect your Mi Account to your phone: Go to Settings → Mi Account and log in. Enable Settings → Additional → Developer → Unlock OEM and Debug over USB.

Download the Mi Unlock Tool

official website

Launch the utility.

Mi

Connect your phone in Fastboot mode

Loudness down + Nutrition

Unlock

If you see a message called Couldn't unlock. You need to wait XX hours, you have to wait, and you can't get around that in 2026, because all the "bypass" methods using old versions of the Mi Unlock Tool or changing the date on the PC stopped working after Xiaomi server updates.

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If you already have a bootloader unlocked on another Xiaomi device, link the same Mi Account to the Redmi 4X – you won’t need to wait 168 hours.

Download firmware for Redmi 4X: where to get and which versions to choose

The choice of firmware depends on your goal:

• 🔄 Recovery is the official MIUI Stable for your region.
• 🆕 Update to the new version of MIUI — MIUI Weekly (weekly builds for enthusiasts).
• 🛠️ Customization and performance — LineageOS, Pixel Experience, or Havoc-OS.
• 🌍 Change region — firmware Global, EEA or China (note: China ROM without Google services!).

Download official firmware only from verified sources:

• The official MIUI website is the Redmi 4X (Santoni).
• Xiaomi Firmware Updater is an archive of all firmware and firmware versions.
• XDA Developers – custom firmware and modifications.

The Redmi 4X is critically aligned with the firmware version and the phone. If you flash the firmware with the newer bootloader version to the old one, the device locks in Fastboot mode with the error "This MIUI version cannot be installed on this device." Check the bootloader version in Fastboot Mode with the command:

fastboot getvar anti

Compare the result with the version in the firmware file name (e.g., santoni_global_images_V12.0.2.0.PCMMIXM_20210310.0000.00_8.0_global_... where 8.0 is the Android version and V12.0.2.0 is the MIUI version).

Firmware methods: Fastboot, Recovery and EDL

There are three main ways to flash Redmi 4X, and the choice depends on the current state of the phone and your goals:

1. Firmware via Fastboot (Mi Flash Tool)

The most reliable method for official firmware is if:

• The phone is switched on but is not working smoothly.
• We need to return the smartphone to factory condition.
• You need to send a firmware for another region.

Step-by-step:

Download the Mi Flash Tool (last version)|Download fastboot firmware for Santoni|Install Xiaomi drivers (Qualcomm) HS-USB QDLoader 9008)|Disable driver signature verification in Windows (if necessary)|Charge your phone at least 50 times%-->

1. Unpack the firmware in a folder without Cyrillic characters (for example, C:\santoni_fastboot).
2. Launch the Mi Flash Tool, press Select and specify the path to the firmware folder.
3. Connect your phone in Fastboot mode (clip Volume Down + Power).
4. In Mi Flash Tool, select firmware mode: clean all – complete cleaning (recommended when changing the region). clean all and lock – cleaning + lock the bootloader (if you need to return the phone to the “factory” state). save user data – data storage (not always working correctly!).

Flash

2. Firmware through Recovery (MIUI or TWRP)

Suitable for updates without loss of data or custom firmware installation. Use MIUI Recovery for official firmware, TWRP for custom ones.

For installation via TWRP:

1. Download TWRP for santoni (version 3.6.2 or later).
2. Fly the recavers through fastboot: fastboot flash recovery twrp-3.6.2-santoni.img fastboot boot twrp-3.6.2-santoni.img
3. In TWRP, make a backup of the NVRAM partition (important for IMEI!), then run the ZIP- firmware file.

⚠️ Attention: When firmware is customized, Redmi 4X firmware is often confused IMEI. To avoid this, save the /nvram folder via TWRP before firmware, or use the IMEI Fix patch (available on XDA for most custom firmware.

3. Firmware through EDL (Emergency mode)

Used if the phone is not turned on (hang on the logo, bootloop, dm-verity error) Requires an authorized Mi Account and a special cable (or close test points on the board).

For Redmi 4X EDL- firmware is possible through the utilities Mi Flash Pro or QFil, but the process is risky - if you make a mistake, the phone can turn into a "brick".

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Firmware through EDL is the last chance to bring the phone back to life, but it takes experience. Without an authorized Mi Account (with unlocked EDL rights), you can't flash it.

Typical Redmi 4X firmware errors and their solutions

Even when following instructions, users often face problems.

If after firmware the phone loads, but there are lags or overheating, try:

• 🔄 Reset the settings to factory (Settings) → Additionally. → Resetting settings).
• 🔋 Calibrate the battery (discharge to 0%, charge to 100% without interruption).
• 🛠️ Switch the kernel separately if the performance is a problem.

Redmi 4X Castom Firmware: What to Choose in 2026

If you are not satisfied with MIUI, Redmi 4X can install alternative firmware based on Android 10-12.

• 📱 LineageOS 18.1 (Android 11) is a stable firmware with minimalist interface. Supports GApps and Magisk.
• 🎨 Pixel Experience (Android 12) is a firmware with design and chips from Google Pixel.
• ⚡ Havoc-OS (Android 10) — high performance and flexible setup.
• 🔒 DivestOS is a firmware with a focus on privacy (without Google services).

Before installing custom firmware:

1. Make sure the loader is unlocked.
2. Slice the TWRP (version 3.6.2 or later).
3. Make a full backup in TWRP (including Boot, System, Data, NVRAM).
4. Format a Data partition (not to be confused with Wipe!) – this will prevent encryption errors.

After installing custom firmware, it may be necessary to:

• 🔄 Switch Magisk for root rights (download from GitHub).
• 📶 Switch IMEI Fix if there is no network (look at XDA for your firmware).
• 🔋 Calibrate the battery (apps like AccuBattery can help track the condition).

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To speed up custom firmware on Redmi 4X, turn off animation in the developer settings (Settings → System → For Developers → Animation Scale = Off).

IMEI Recovery After Firmware

One of the most common problems after firmware custom firmware on Redmi 4X is the loss of IMEI (phone does not catch the network, in the settings shows IMEI: null), this occurs due to damage to the NVRAM partition where the modem data is stored.

Recovery methods:

1. Backup recovery: If you've been backing NVRAM in TWRP, restore it. Or copy /data/nvram from the backup to the appropriate section.
2. Manual IMEI (requires root): su setprop sys.usb.config diag,adb Then use the Maui META or SN Write Tool utility to write IMEI.
3. Custom firmware patch: Download IMEI Fix for your firmware (search XDA or 4PDA). Sweep the ZIP- file through TWRP.

⚠️ Warning: Changing IMEI may be illegal in some countries.In Russia and most CIS countries, it is only allowed to restore the original IMEI. Using someone else's IMEI or generating random values may result in a network lock by an operator.

FAQ: Frequent questions about Redmi firmware 4X