Firmware Xiaomi Redmi smartphone via Fastboot is one of the most reliable ways to update or restore the system when standard methods do not work.This mode allows you to install official or custom firmware directly through the computer, bypassing the limitations of MIUI. However, the process requires care: an error at any stage can lead to a “brick” of the device (complete failure).
Unlike the Settings → About phone → System update, Fastboot’s firmware gives you full control of the installation, but also carries more risks. For example, an incorrectly selected firmware version for the Redmi Note 10 Pro model instead of the Redmi Note 10 can make the phone unusable. In this article, we will discuss all the steps from preparation to solving typical problems, with an emphasis on circumventing the new restrictions of Xiaomi 2026, including mandatory binding of the Mi Account before unlocking the bootloader.
What is Fastboot and When You Need It
Fastboot is a protocol for interacting with the Android bootloader via USB, allowing you to install firmware, unlock the bootloader, or restore the system when the smartphone is not booting. In the case of Xiaomi Redmi, this mode is used in three main scenarios:
- 🔄 Recovery after a crash: if the phone is stuck on the logo MI or cyclically rebooted (bootloop").
- 📱 Downgraid version MIUI: Return to the old firmware if the new one is not working properly.
- 🔓 Install custom firmware (such as LineageOS or Pixel Experience), but only after unlocking the bootloader.
It is important to understand that Fastboot ≠ Recovery. Recovery mode (access via Power) + Volume Up) firmware is installed from internal memory or SD-The Fastboot requires a PC connection, and Xiaomi blocks the bootloader by default, so you need to unlock it before you run the firmware — more on that in the next section.
Preparation for firmware: what to do before the start
Incorrect preparation is the main reason for the failure of firmware. Before you put Redmi in Fastboot mode, follow the following steps:
- Check the model of the device. Go to Settings → About Phone → Model and write down the exact name (e.g. Redmi Note 12 Pro+ 5G, not just "Redmi Note 12"). The firmware for another model will lead to a hard brick.
- Download the correct firmware. The official versions of MIUI are available at en.miui.com. Choose Fastboot ROM (file with the.tgz or.zip extension).
- Install drivers and tools: 🖥️ Mi Flash Tool (official utility from Xiaomi for firmware in Fastboot). 🔌 ADB Fastboot (part of Google’s Platform Tools). 🔄 Qualcomm drivers (if your Redmi is on a Snapdragon processor).
Charging the battery
Pay special attention to unlocking the bootloader. Since 2026, Xiaomi has tightened the rules: now you need to link your Mi Account to the device 7 days before unlocking. Without this step, you can not flash custom firmware or even an official MIUI through Fastboot.
☑️ Checklist before firmware
Unlocking the bootloader on Xiaomi Redmi: step-by-step instructions
The bootloader on all Xiaomi smartphones is locked by default. To flash the device through Fastboot, it must be unlocked. The process takes at least 7 days due to the mandatory account binding.
- Link your Mi Account: Go to Settings → Xiaomi account and log in. Enable Settings → Additional → Developers → Unlock OEM. Connect your device to the Internet and wait for notifications of successful linking (can take up to 24 hours).
Download the Mi Unlock Tool
en.miui.com/unlock
Launch the utility.
Wait 168 hours.
⚠️ Warning: Unlocking the bootloader resets all data on the phone (factory reset). Backup photos, contacts and apps in advance through Settings → System system → Backup.
What happens if you break the unlock?
How to flash Xiaomi Redmi through Fastboot: detailed instructions
When the bootloader is unlocked and the firmware is downloaded, you can start installing it.
- Unpack the firmware. The archive with the extension.tgz or.zip should be removed to the folder without Cyrillic characters (for example, C:\Redmi_Flash\).
- Launch the Mi Flash Tool on behalf of the administrator. Press Select and point the path to the unpacked firmware.
- Connect your phone in Fastboot mode: Turn off Redmi. Press Power. + Volume Down before the Fastboot logo appears.Plug in USB-cable to PC (it is desirable to use the original cable).
Select firmware mode
- Clean all – complete data cleanup (recommended when changing the MIUI version).
- Clean all and lock – cleaning + lock loader (for official firmware).
- Save user data – saving data (risky, can lead to errors).
- Press Flash and wait until it is completed (usually 5-15 minutes).
If the process is successful, the phone will automatically restart. The first turn on can take up to 10 minutes - do not interrupt it.
1. Reinstall drivers manually through Device Manager (select "Qualcomm HS-USB QDLoader 9008").
2. Use another USB-Port (preferably 2.0, not 3.0).
3. Disable driver signatures in Windows (via Run) → gpedit.msc).-->
Common Firmware Errors and Their Solutions
Even with the correct following of the instructions, errors can occur. Below is a table with the most common problems and ways to fix them:
| Mistake. | Reason. | Decision |
|---|---|---|
| Couldn't find fastboot | Mi Flash Tool is not a detector device | Check USB connection (try another cable/port). Install drivers manually. Run Mi Flash Tool on behalf of the administrator. |
| Flash is not done | Incompatible firmware or a corrupted file | Download the firmware again (check the hash amount). Select a different mode (Clean all instead of Save user data). |
| Anti-rollback check | Trying to install an old version of MIUI | Update to the latest version via OTA, then stitch. Use firmware with the same or higher Anti-rollback index. |
| The phone does not turn on after the firmware | Hard brick due to incorrect firmware | Try flashing it back in EDL mode (requires an authorized Xiaomi account). |
⚠️ Note: If after the firmware Redmi stuck on the logo MI, Don't panic. Try to go to Recovery. + Volume Up) and make Wipe data. If that doesn't work, repeat the firmware with the Clean all option option option option.
Firmware custom firmware: features and risks
In addition to the official MIUI, many users install custom firmware (such as LineageOS, Pixel Experience or HavocOS), which gives more options for customization, but also carries additional risks:
- ⚡ Loss of warranty: Xiaomi does not support custom firmware, when contacting the service center may refuse repairs.
- 📵 Problems with the module: some firmware stops working NFC, camera 5G.
- 🔋 Increased battery consumption: Unoptimized cores could cut battery life.
If you decide to install custom firmware, follow this algorithm:
- Unlock the bootloader (as described above).
- Install custom Recovery (TWRP or OrangeFox) via Fastboot: fastboot flash recovery twrp.img fastboot boot twrp.img
- In Recovery, make a full backup (Backup → Select all partitions).
- Sweep through firmware and GApps (if you need Google services).
⚠️ Attention: Some custom firmware requires additional manipulation, such as kernel firmware or vendor section fixes. Always read the firmware author's instructions on the forum XDA Developers or 4PDA.
💡
Custom firmware gives you more freedom, but it takes away official Xiaomi support.Be sure that the firmware is compatible with your Redmi model and has positive user feedback before installing.
Recovery after a failed firmware
If something goes wrong and Redmi stops turning on, don't rush to bring it to the service. In most cases, the device can be restored by yourself:
- 🔄 Fastboot Firmware Replay: Try to Switch the Same Version MIUI Once again, select the Clean All option.
- 🛠️ Regime. EDL: If Fastboot doesn’t respond, transfer your phone to Emergency Download Mode (requires special cable or test points).
- 📥 Recovery via Mi Assistant: Xiaomi’s official disaster recovery utility (not available on all models).
EDL mode requires an authorized Xiaomi account (you can buy on specialized forums) and Mi Flash Pro. The process is more complicated than in Fastboot, but often this is the only way to reanimate a bricked-up phone.
If none of the methods worked, contact the service center. Indicate that the phone was sewn through the Fastboot, this will help the wizard to diagnose the problem faster. The cost of recovering from a failed firmware is usually 1-3 thousand rubles (depending on the model).