How to reinstall Android on Xiaomi Redmi 9

Modern smartphones, despite their powerful hardware, may experience software glitches over time. Model Xiaomi Redmi 9, being one of the most popular budget employees, is no exception. Users often encounter freezes, errors in the system, or the desire to update to a new version MIUIthat does not arrive over the air. In such situations, the only correct solution is to completely reinstall the operating system.

This process requires care and strict adherence to the algorithm of actions. Incorrect firmware can turn a device into a “brick,” so it is important to understand the difference between a simple reset and deep flashing through special modes. We will analyze all available methods: from a standard reset to using the mode Fastboot i Recovery.

Before starting any manipulations, it is critical to save all personal data. Reinstalling the system involves completely formatting the internal memory. Photos, contacts and correspondence in instant messengers will be permanently deleted if you do not make a backup copy in advance. Use cloud services or transfer files to your computer.

Preparing the device for flashing

The success of the operation depends 90% on the quality of preparation. The first step is to make sure that the battery is charged at least 60%. The process of writing data to flash memory is energy-intensive, and if the phone turns off in the middle of the process, recovery will be extremely difficult. Connect the smartphone to the original charger and let it stand for about an hour.

Next you should take care of the drivers. The computer should correctly recognize your device in different operating modes. Xiaomi Redmi 9 usually requires standard ADB drivers and specific Qualcomm or MediaTek drivers, depending on the regional version of the processor. They can be found in the official Mi Flash Tool package or on specialized forums.

⚠️ Attention: Menu interfaces and item names may vary slightly depending on the version of MIUI (12, 12.5 or 13). Always check the current screenshots for your specific build before pressing buttons.

You will also need a quality USB cable. Cheap "charge only" cables do not transfer data, which will make it impossible to connect to a PC for firmware. Use the original cable included in the kit or a certified analogue that supports high-speed data transfer.

Full reset method via the Recovery menu

The safest and easiest way to “reinstall” the system is to perform hard reset via the built-in recovery menu. This method does not require a computer and is suitable for eliminating most software glitches, slowdowns and account login errors.

To enter the mode Recovery you must completely turn off your smartphone. Then hold down the Volume Up button and the Power button at the same time. Hold them until the logo appears Redmi, then release the power button, but continue to hold the volume until the main menu appears.

Navigation in this menu is carried out using the volume buttons (up and down), and selecting an item is done using the power button. You need to find the section Wipe Data. Inside it, select the option Wipe All Data. The system will ask you to confirm the action, since this is an irreversible process.

• 🔍 Select the item Confirm to start cleaning.
• ⏳ Wait for the process to complete, the progress indicator will fill.
• 🔄 After a successful reset, select Back to Main Menu.
• 🔌 Press Rebootthen Reboot to System.

The first boot after the reset may take 5 to 10 minutes. This is normal, the system is performing initial file setup and indexing. Do not try to forcefully reboot the phone during this period, even if the screen remains black with the logo for a long time.

Installing firmware via Recovery mode (Local Update)

If a simple reset doesn't help, or you want to update to a more recent version of the shell without losing data (although a backup is still advisable), you can use the local update method. You will need to download the firmware file with the extension .zip for your model.

It is important to download the Recovery ROM, and not the Fastboot ROM. The file should weigh about 2-3 GB. Place the downloaded archive in the root directory of your phone's internal memory or SD card so that it is easy to find. Name the file simply, for example update.zipto avoid encoding errors.

Go to the phone settings, select About the phone and click on the MIUI version icon. In the upper right corner, click on the three dots and select Select firmware file. Specify the path to the downloaded archive. The system will check the integrity of the package and offer to start installation.

Firmware type	File extension	Installation method	Saving data
Recovery ROM	.zip	Through the update or Recovery menu	Possible (if you select "Without cleaning")
Fastboot ROM	.tgz	Only via PC and Mi Flash	No (full cleaning)
OTA Update	Automatically	Via the Internet	Yes

After confirmation, the phone will reboot and begin installation. The screen may go off and on several times. The process takes about 10-15 minutes. Upon completion, the device will boot into the updated system.

What to do if the system says “Unable to update”?

This error occurs if you try to roll back to an older version of Android or MIUI. Anti-Rollback protection prevents the installation of previous software versions. The solution is to use a method with complete data clearing via Fastboot.

Deep flashing via Fastboot mode

This is the most radical and effective method that allows you to restore your phone even after serious errors when the system does not boot. To do this, you will need a computer, a utility Mi Flash Tool and unzipped firmware in Fastboot format (extension .tgz).

Switch your smartphone to Fastbootmode. To do this, turn off the phone, then hold down the volume down button and the power button at the same time. An image of a hare in a hat with earflaps will appear on the screen, repairing an Android robot, and the inscription FASTBOOT. Connect the phone to the PC with a cable.

Run Mi Flash Tool as administrator. Click the button Refreshso that the app sees your device (the serial number will be displayed). Click Select and specify the folder with the unpacked firmware. The path to the folder should not be. contain Cyrillic characters or spaces.

⚠️ Attention: At the bottom of the Mi Flash Tool there are three firmware modes. For a clean installation, select clean all. Mode clean all and lock will block the bootloader, which can be dangerous if you are using unofficial firmware.

Press the button Flash to start the process. A progress bar will appear in the status window. Do not disconnect the cable or touch the phone until the green message appears. SuccessAfter this, the phone will automatically reboot. data-i="105">📊 What firmware method do you plan to use?

Unlocking the bootloader and custom firmware

Many enthusiasts want to install custom firmware (for example, LineageOS or Pixel Experience) to get pure Android without unnecessary water and unnecessary software. However, Xiaomi Redmi 9 comes with a locked bootloader.

To unlock, you need to submit an application on the official Xiaomi website, link your Mi account to the device in the settings and wait a waiting period (usually from 7 to 15 days). After obtaining permission, the utility is used Mi Unlock Tool on the PC.

The unlocking process completely erases all data from the phone. After successful unlocking, the Fastboot menu will appear. inscription Device State: Unlocked in orange. This opens access to the installation of Custom Recovery (for example, TWRP), through which you can flash any modified system images.

• 🔓 Unlocking will void the warranty on the device.
• 🛡️ Some banking applications may stop working without additional settings. (Magisk).
• 📉 The wide-angle camera may not work correctly on some custom builds.

If you are not an experienced user, it is recommended to stay within the official MIUI firmware. They are optimized specifically for hardware. Redmi 9 and provide better stability of the communication modules and camera.

Possible errors and ways to solve them

During the firmware process, they may occur various errors. One of the most common is Error: Missmatching image and device. This means that you are trying to install the firmware for another model (for example, Redmi 9C or global version to Chinese). Always check the model code name (codename), this is common for Redmi 9 lancelot.

Another common problem is getting stuck on the logo (bootloop). If this happened after unsuccessful firmware, try entering Recovery mode again and do Wipe Data. If it doesn’t help, you will have to return to the Fastboot method and flash the stock image again.

Error Can't validate auth when unlocking the bootloader is often associated with a mismatch between the Mi account linked in the phone settings and the account under which you logged into the Mi Unlock utility. Make sure that a SIM card with Internet is inserted and you have waited for the mandatory waiting period.

Is it possible to flash the global version on the Chinese Redmi 9?

Technically this is possible, but requires unlocking the bootloader. Simply changing the region in the settings will not work. When cross-region flashing, be sure to use the "Clean all" mode to avoid system file conflicts.

Will IMEI disappear after flashing?

When using official firmware and standard tools (Mi Flash, Recovery), the partition with IMEI is not affected. Losing IMEI is only possible if you work incorrectly with low-level partitions through engineering menus or custom scripts.

How long does a complete flashing take?

The recording process via Fastboot itself takes 200-400 seconds. However, taking into account the preparation, downloading files (2-3 GB) and the first boot of the system, allow about 40-60 minutes of free time for the entire procedure.

Is it safe to interrupt the process if it is frozen?

No, this is a critical error. Interrupting writing to the system or boot partition is almost guaranteed to result in the phone not working. If progress does not move for more than 20 minutes, try changing the USB port or cable, but do not turn off the power abruptly.