Why do you want to replay the Redmi Note 4X in 2026?
Xiaomi Redmi Note 4X (codenamed mido) despite its age (released in 2017) remains a popular device among customization enthusiasts. In 2026, the current reasons for reflashing this smartphone are the lack of official updates (the last MIUI 12.5.7 was released in 2022), outdated versions of Android (maximum Android 7.0 Nougat in the runoff) and the desire to install modern custom firmware like LineageOS 20 or Pixel Experience 13.
Flashing not only allows you to upgrade Android to 12-13, but also get rid of the built-in Xiaomi software, improve performance with kernels with optimized power consumption, and get support for modern applications that require Android 10+. However, the process is fraught with risks, from “brick” (turning the phone into a “brick”) to the loss of IMEI. This instruction covers all the steps from unlocking the bootloader to installing TWRP and selecting firmware.
Preparation for firmware: what to do before the start
The first step is to back up all the data. The firmware erases the internal memory (/data), so copy photos, contacts and files to your PC or cloud. Use Mi Mover to port applications or adb backup to create a full copy:
adb backup -apk -obb -shared -all -f backup.abNext, check the bootloader version and device model:
- Go to Settings → About Phone → MIUI version and tap 7 times on the “Kernel Version” line to activate Developer Mode.
- Return to Settings → Additional → For developers and enable USB Debugging and OEM Unlocking.
- Install the Mi Unlock Tool (version 5.5.224.30 or later) and log in with the same Mi Account as your phone.
Download the necessary files (links are valid for 2026):
- 🔧 Official firmware MIUI (Choose Fastboot or Recovery for Mido)
- 🔄 TWRP 3.7.0 (last stable version for Redmi Note) 4X)
- 📱 Pixel Experience 13 (Android 13 for mido)
- 🔓 List of custom firmware with mido support
Install Qualcomm drivers on PC| Download firmware and TWRP for mido| Charge your phone at least 70% | Disable antivirus (can block Mi Unlock Tool) | Connect your phone to the rear USB 2.0 port (not 3.0!)
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⚠️ Please note: if your Redmi Note 4X purchased in China (version) mido_cn), Unlocking the bootloader may require waiting until 360 hours (15 days) after the account is linked. Check the model in Settings → The phone. → Model: Unlocking the bootloader: bypassing the restrictions Xiaomi has imposed strict restrictions on unlocking the bootloader for older models. 4X into 2026 The following rules apply in the year: 🔗 Mi Account should be linked to a phone at least 72 hour (3 day) before attempting to unlock. 📡 The phone must be connected to a mobile network or Wi-Fi during the period of time. 30 Days (checked by Xiaomi servers). 🔐 You can unlock no more on one account. 1 device 30 Unlock instructions: Launch Mi Unlock Tool on behalf of the administrator. Sign in with the same account as your phone. Turn off the phone, press the volume down. + Power to log in to Fastboot. Connect your phone to your PC. In the program, press Unlock. If there is a Couldn't unlock error, wait for the specified time (from the specified time). 72 before 360 What to do if the Mi Unlock Tool gives you an error 86006? This error means that Xiaomi server has not confirmed the account’s link to the device: 1. Wait. 3-5 days and try again. 2. Check that the phone is on mobile Internet (Wi-Fi is not enough). 3. Try using another PC or virtual machine with Windows 7 (sometimes). 4. If the phone is bought from hand, the previous owner must untie the account through Mi Account. ⚠️ Warning: After unlocking the bootloader, all data, including internal memory, will be reset (/data). It can also be erased. IMEI — Save it in advance with the app MTK Engineering Mode (Entry Code: ##3646633##). Installation TWRP: stock-Recovery TWRP (Team Win Recovery Project is a custom recovery required to install unofficial firmware. 4X recommended 3.7.0_9-0, As new builds may not support mido, installation instructions: Download twrp-3.7.0_9-0-mido.img and rename the file to recovery.img. Place it in a folder with fastboot (for example, C:\platform-tools\). Turn off the phone and log in to Fastboot (Loudness Down) + Connect your phone to your PC and execute the command: fastboot flash recovery recovery.img After successful firmware, execute: fastboot boot recovery.img to load up immediately TWRP. V TWRP You need to disable the verification of the firmware signature, otherwise custom ZIP-Files will not be installed: Go to Mount → Disable DM-Verity. Run the Wipe → Format Data (this will remove encryption and allow you to install firmware). 💡After installation TWRP The phone is loaded into stock recavers, repeat the command fastboot flash recovery recovery.img And immediately perform fastboot boot. recovery.img. Xiaomi stock Recovery automatically rewrites TWRP first loading. Selection of firmware: official MIUI vs custom builds In 2026 for Redmi Note 4X Two types of firmware are available: Firmware type Advantages Advantages Disadvantages Recommended version Official MIUI Stability, support OTG, All camera features run Android 7.0, plenty of bloatware, no security updates MIUI 12.5.7 LineageOS Android 13, clean interface, regular updates Not working IR-blaster, possible bugs with Wi-Fi LineageOS 20 Pixel Experience Interface as on Google Pixel, Android 13 Poor battery optimization, bugs with PixelExperience 13 Havoc-OS camera Maximum customization, Android 12 Complex setup, possible random reboots Havoc-OS 5.12 For beginners recommended LineageOS is the most stable and has an active community. If you want maximum performance, try the Pixel Experience, but be prepared for battery issues (the battery sits on the back of the battery). 20-30% It's faster than the drain. MIUI|LineageOS|Pixel Experience|The other custom|I haven't decided yet.--> ⚠️ Attention: Firmware based on Android 12+ may not support 32-bit applications. If you need old games (e.g, GTA San Andreas, choose firmware on Android 10-11. Firmware through TWRP: Installation of custom firmware through TWRP consist 5 Don't miss any of them, it's a bootloop. File copy: Downloaded firmware (ZIP) Put your GApps (if you want Google services) on microSD or internal memory. ZIP-file! Cleaning up sections: Wipe → Advanced Wipe → Mark Dalvik, Cache, System, Data → Swipe to Wipe Installation of firmware: Install → Choose. ZIP firmware → Swipe to Confirm Flash Installation GApps (optional): Install → Select GApps (arm64, Android 13) → Swipe to Confirm Flash Reboot: Reboot → The first loading system may take 10-15 If after firmware, the phone is stuck on the Xiaomi or LineageOS logo more 20 minute: 🔄 Go back in TWRP (Loudness up + Nutrition). 🧹 Run the Wipe. → Format Data (this will delete all data, but often solves the problem). 🔧 Refresh the firmware. 💡If the firmware requires additional fixes (for example, for the camera or Wi-Fi), they should be installed immediately after the main fix. ZIP-file without restarting the phone, or you'll have to repeat the process from scratch. Fastboot Firmware: The Official Method If You Prefer the Official MIUI, It can be installed via Fastboot using the MiFlash utility, which is suitable for recovering the phone from a "brick" or returning to stock firmware. Instructions: Download the Fastboot firmware for mido and unpack it into a folder without spaces (for example, download the Fastboot firmware for mido, C:\mido_fastboot\). Install Platform Tools and MiFlash Tool. Turn off your phone and log in to Fastboot. In MiFlash, click Select, specify the firmware folder, select Clean all at the bottom and press Flash. Wait for the green tick to appear (the process takes time). 3-5 If MiFlash is giving you an error flash_all_lock.bat failed: 🔧 Rename the file flash_all_lock.bat into flash_all.bat. 🖥️ Launch it on behalf of the administrator. 🔄 If the error is repeated, try another one. USB-port. ⚠️ Note: After Fastboot firmware is installed, the bootloader will automatically lock. If you're planning to install custom firmware, first unlock it again through the Mi Unlock Tool. Solving common problems after firmware Even if you install the firmware properly, here are the most common ways to solve them: Problem Possible Reason No Mobile Network (IMEI Disappeared) Delete the modem section when firmware Restore IMEI through MTK Engineering Mode or QCN-Phone file is not charged Incompatible core in custom firmware Install firmware with a patch for battery charging or return to MIUI Camera is not working, there are no drivers for Sony IMX258 Install. Camera2API Fix Wi-Fi/Bluetooth not included Involved Damaged section firmware Scroll firmware from stock firmware through TWRP If the sensor doesn’t work after the firmware, it’s likely that the firmware isn’t compatible with your Redmi Note version. 4X. Check the model: 📱 Mido – Global version (Snapdragon) 625). 📱 nikel - Chinese version (Snapdragon) 625, But with other mods. nikel firmware is not good for mido. IMEI post-fix? 1. Download. MTK Engineering Mode. 2. Enter the code ##3646633## → Go to Connectivity → CDS Information → Radio Information. 3. In the field AT+ enter: AT +EGMR=1,7,"IMEI_1" AT +EGMR=1,10,"IMEI_2" (substitute IMEI_1 and IMEI_2 on your original IMEI). 4. Reboot the phone. FAQ: Frequently Asked Questions about Redmi Note 4X Xiaomi blocks installation of any firmware other than official through MIUI Updater, if the bootloader is locked. For custom firmware (LineageOS, Pixel Experience) or even manual installation of the official MIUI Fastboot requires unlocking. How to check if the bootloader is unlocked? Turn off the phone and press the volume down. + Power to enter the Fastboot if there's a sign at the bottom of the screen. UNLOCKED And the yellow lock icon -- the bootloader is unlocked. LOCKED — You need to use the Mi Unlock Tool. Which firmware is best for games on Redmi Note? 4X? Havoc-OS or Corvus is recommended for gaming. OS These firmwares are optimized for performance and support Vulkan. API, What is important for modern games (Genshin Impact, Call of Duty Mobile) Avoid firmware on Android 12+ — They might be slowing down because there's not enough drivers for the Adreno 506. MIUI after installing custom firmware? Yes, but with the caveat: Make a backup of the current firmware in the TWRP (Backup → System, Data, Boot. Download the desired version MIUI Fastboot and run it through MiFlash. After rollback, unlock the bootloader again (it will lock automatically). Important: The rollback to Android 6.0 or lower may result in loss of IMEI! Where to download the original drivers for Redmi Note 4X? Qualcomm Official Drivers for Redmi Note 4X You can find it on the Qualcomm Developer Network (Snapdragon section) 625). In the stock firmware archive (folder) images\ contain modem.img, boot.img In the forum 4PDA (Theme of mido: Recovery IMEI Or Baseband, go through. modem.img and fsg.mbn via Fastboot: fastboot flash modem modem.img fastboot flash fsg fsg.mbn