Xiaomi Redmi 4X Pro (codenamed santoni) is still popular with users due to its balanced features and the ability to install current firmware. However, over time, the regular MIUI begins to slow down and official updates stop coming out, flashing the device can return to its former performance, add new features or even install a clean Android.
In this article, we will discuss all the steps of the process, from preparing the device to installing firmware through Fastboot or TWRP Recovery. Particular attention will be paid to unlocking the bootloader on the Redmi 4X Pro, taking into account changes in Xiaomi policy from 2023 to 2026, since without this step, installing custom firmware is impossible.
If you're a beginner, don't be intimidated by terms like EDL or adb, we'll explain it in plain language. For experienced users, we'll give commands and links to relevant tools. The rule of thumb is: follow the instructions consistently and don't skip the steps!
Preparation for Flashing: What You Need to Know Before You Start
Flashing isn't just an update through the settings menu, it's a complete replacement for smartphone software that can both make it work better and turn it into a brick if you do something wrong. Before you get started, answer three key questions:
- 🔹 Why? Would you like to install custom firmware (like LineageOS or Pixel Experience) and return the official firmware to the original. MIUI After the crash, or simply upgrade to the latest version?
- 🔹 What firmware? Official (from Xiaomi) or unofficial (castom)? The latter are often devoid of Bloatware but may have bugs.
- 🔹 Are you prepared for risks? Wrong actions can lead to loss of warranty, blocking IMEI or.
There are several types of firmware available for the Redmi 4X Pro:
- 📱 Official. MIUI — stable, but with limitations (for example, locking the loader).
- 🛠️ Castom firmware based on Android (AOSP) — without Xiaomi services, but with more freedom.
- 🔄 Port assemblies - for example, MIUI from other regions (Global, China, China, EEA).
⚠️ Attention: On Redmi 4X Pro (as with other Xiaomi models) from 2023, there is a new policy of unlocking the bootloader.Now it requires linking the Mi Account to the device and waiting 7-15 days!
Before the process begins, it is mandatory to:
- Back up your data (photos, contacts, messages) to your computer or cloud.
- Charge the phone to at least 60% – flashing can take up to 30-40 minutes.
- Prepare. USB-cable (preferably original) and computer under control Windows/Linux.
Unlocking the bootloader on the Redmi 4X Pro: step-by-step instruction 2026
The bootloader on all Xiaomi smartphones is locked by default, which is a security measure, but it also makes it harder to flash it.
- 🔓 Custom firmware installations (TWRP, LineageOS and others.).
- 🔄 Restore the device via Fastboot or EDL.
- 🛠️ Getting root rights (for example, through Magisk).
The unlocking process has changed since 2023 and now includes two mandatory steps:
- Linking your Mi Account to your device (unless previously done).
- Waiting for confirmation (from 7 to 15 days) after sending a request.
Instructions:
- Turn on the phone Developer Mode: go to Settings → About Phone → MIUI version and tap it 7 times.
- Back to Settings → Additionally. → For developers and activate: 🔧 Debugging by USB 🔓 Unlocking OEM (if there is an option)
Connect the phone to your computer and confirm the debugging permission.
Mi Unlock Tool
Launch the program, log in to your Mi Account (should match the one tied on your phone) and follow the prompts.
⚠️ Note: If you see a Couldn’t unlock or Device not bound error when unlocking, then the Mi Account is not tied to the phone, and this is corrected only through a wait (7-15 days) or by contacting Xiaomi with proof of purchase.
Once successfully unlocked, the phone will automatically reset to factory settings, and you can now start the firmware.
Linking your Mi Account to your device|Enable the developer mode|Activate debugging by USB|Download Mi Unlock Tool 2026|Wait 7-15 days (if required)-->
Selection of firmware for Redmi 4X Pro: official vs custom
The type of firmware that determines not only the functionality, but also the stability of the device, and let's look at the pros and cons of each variant for the santoni.
| Type of firmware | Pluses | Cons | Recommendation |
|---|---|---|---|
| Official MIUI | ✅ Stable work✅ Support OTG all functions of the camera✅ Regular security updates | ❌ Lots of Bloatware (pre-installed applications)❌ Restrictions on customization❌ Advertising in the system menu | For everyday use |
| Castomic (AOSP) | ✅ Clean Android without unnecessary apps✅ More opportunities to set up✅ Longer supported (for example, Android 12 for Redmi) 4X) | ❌ Possible bugs with camera or sensors❌ No encryption by default❌ Requires manual updates | For experienced users |
| Port MIUI | ✅ Keeps the Xiaomi corporate interface✅ You can choose a version for another region.✅ Often optimized better than the official | ❌ Risk of incompatibility with iron❌ Possible problems with OTA-update | If you need MIUI, but the official does not suit |
Where to download firmware:
- 🌐 Official: Xiaomi website (choose the version for santoni).
- 🛠️ Castomy: XDA Developers or SourceForge.
- 🔄 Ports MIUI: Telegram channels, like, MIUI Updates Tracker or Xiaomi Firmware Updater.
For beginners, we recommend starting with the official firmware. If you want to try custom, choose proven builds marked Stable and user reviews.
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Before downloading the firmware, check its hash amount (MD5/SHA1) with a utility like HashMyFiles.
Install firmware via Fastboot: detailed instructions
Fastboot is a boot mode that allows you to flash the device directly from your computer, and it is suitable for installing official Xiaomi firmware (with the extension.tgz or.zip) and some custom ones, the advantage of which is reliability, since the firmware is low.
What you need:
- 🖥️ Windows computer 10/11 Linux.
- 🔌 USB-cable (preferably original).
- 📁 Firmware for santoni in Fastboot format.
- 🛠️ Utilities: Platform Tools (ADB and Fastboot, Mi Flash Tool.
Step-by-step:
- Unpack the archive with firmware in a folder without Cyrillic characters (for example, C:\santoni_fastboot).
- Turn off your phone and press Volume Down + Power to enter the Fastboot (a rabbit in a hat will appear on the screen).
- Connect your phone to your computer. The Android Bootloader Interface should appear in the Device Manager.
- Launch the Mi Flash Tool, press Select and specify the folder with the firmware.
- Select firmware mode: Clean all - complete cleaning (recommended when changing the version of MIUI); Clean all and lock - cleaning + lock bootloader (only for official firmware!); Save user data - saving user data (risky, can lead to bugs).
Flash
If the process is stuck on Waiting for device, check:
- 🔌 Cable and port USB (Try another port or cable).
- 🖥️ Drivers installed (can be downloaded via Platform Tools).
- 🔓 Is the bootloader unlocked (if not, go back to the previous section).
⚠️ Note: If you are applying for an official MIUI With the lock and lock, the unlock will reset after the restart. To re-install the custom firmware, you'll have to repeat the unlock process!
What to do if the Mi Flash Tool gives you a “flash not done” error?
Install custom firmware through TWRP Recovery
If you want to install LineageOS, Pixel Experience or other custom firmware, you will need to TWRP Recovery is an alternative recovery menu. It allows you to flash through the ZIP-files, backups and root rights.
For Redmi. 4X Pro is a good version TWRP developer bruno_martins (It's encryption-enabled. You can download it. XDA.
Instructions for installing TWRP and firmware:
- Download the image TWRP (twrp-3.6.1_9-0-santoni.img) and firmware (e.g, lineage-19.1-20231210-UNOFFICIAL-santoni.zip).
- Move it. ZIP-a firmware file on the phone's internal memory or SD-map.
- Turn off the phone and press Volume Up + Power to log into the Fastboot.
- Connect your phone to your computer and execute the command: fastboot flash recovery twrp-3.6.1_9-0-santoni.img
- Without turning off the cable, press Volume Up + Power to immediately log into TWRP (otherwise the system will overwrite recovery).
- V TWRP run the Wipe → Advanced Wipe and mark: 🗃️ Dalvik / ART Cache 📱 System 📁 Data 🔄 Cache
Then swipe for confirmation.
Install
Reboot System
The first launch of custom firmware can take 10-15 minutes — that’s normal. If the phone has been stuck on the logo for more than 20 minutes, then something has gone wrong (possibly incompatible firmware or incorrect wipe).
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Always check firmware compatibility with the santoni model. Installing firmware for Redmi 4 (not Pro) or Redmi 4A will result in a device breaking down!
Solving problems after flashing
Even if you follow the instructions accurately, sometimes you get errors, and let's look at the most common ones and how to fix them.
| Problem. | Possible cause | Decision |
|---|---|---|
| Phone not turned on (black screen) | Incorrect firmware or interrupted process | Repeat the firmware via Fastboot or EDL (Emergency Mode) |
| Hanging on the MI or Android logo | Incompatible firmware or incomplete wipe | Log in to TWRP and repeat Advanced Wipe, then reflash. |
| No network (IMEI lost) | The modem or EFS partition is damaged | Restore the IMEI via QCN or run the official MIUI |
| Camera or sensors are not working. | There are no drivers in the custom firmware | Install a patch for the camera (like the ANX Camera) or return to MIUI |
If your phone has turned into a brick, don't panic. In 90% of cases, it can be restored through EDL (Emergency Download Mode).
- 🖥️ The Mi Flash Tool program is in mode EDL.
- 🔧 Cable with 9008 port support (or original) USB Xiaomi).
- 📁 Firmware in.tgz format for santoni.
Instructions for EDL:
- Turn off the phone.
- Close the contacts test point on the motherboard (for Redmi) 4X Pro is two contacts next to the battery and connect USB-cable.
- The device manager should appear Qualcomm HS-USB QDLoader 9008.
- In the Mi Flash Tool, select the firmware and press Flash.
⚠️ Warning: Test point requires disassembling the phone and can damage the board.If you're unsure of your skills, contact the service center.