Reflashing Xiaomi Redmi 9A: official and custom firmware

Xiaomi Redmi 9A is one of the most popular budget smartphones, but over time its performance can be reduced due to outdated software. Flashing the device helps not only to update the system to the current version, but also to eliminate bugs, improve performance or even install custom firmware with advanced features. However, the process requires care: wrong actions can lead to a “brick” (complete inoperability) of the phone.

In this guide, we will take a look at all the ways Redmi 9A can be flashed, from official updates via MIUI Updater to manual installation via Fastboot and Recovery, focusing on device preparation, bootloader unlocking and solutions to common bugs. If you’re a beginner, we recommend starting with the official methods, which are safer and don’t require deep technical knowledge.

Before you start, make sure your Redmi 9A has a dandelion model. This is critical, as firmware for other models (e.g. Redmi 9C or Redmi 9) will not work. You can check the model in the settings: Settings → About phone → Model.

1. Preparation for flashing: what to do before the start

Flashing is a process that can go wrong if you don't follow the initial steps. First and foremost, back up all the data. Even if you plan to upgrade without reset, there's always a risk of losing information. Use Mi Cloud, Google Drive, or local copying on your PC.

Second, check the battery power. It should be at least 60 percent, and if the phone runs out during firmware, it can cause serious malfunctions.

• 🔌 Cable USB Type-C (original or high-quality)
• 💻 Computer with Windows/Linux (for the Fastboot methods and ADB)
• 📱 Xiaomi Drivers (Install Mi) PC Suite)
• 🔓 Unlocked bootloader (if you plan a custom firmware)

If you're going to install an informal firmware, be sure to unlock the bootloader through the official Mi Unlock Tool. Without this, custom firmware won't install. Note: unlocking resets the phone to factory settings!

⚠️ Attention: If your Redmi is 9A If you bought it in China, it can have a regional lock, in which case you will need to link your Mi Account to the device and wait 7-15 days to unlock the bootloader (by Xiaomi rules).

Make a data backup|Check the battery charge (>60%)|Install Xiaomi drivers|Download the right firmware|Unlock the bootloader (for custom firmware)|Connect the original USB-cable-->

2.Official Update Methods: MIUI Updater and Recovery

The safest method is to upgrade through built-in MIUI tools, which is suitable for installing official stable or beta versions of firmware without risking losing warranty, and there are two options: through the System Update app or manually through Recovery.

Update via MIUI Updater

This method does not require a computer and is suitable for most users. Open Settings → About Phone → System Update. If a new version is available, click Download and wait until you finish. After download, select Reboot and install.

If the update does not come automatically, check:

• 🌍 Firmware region (your region, for example, Russia or Global, should be selected in the settings)
• 🔄 Beta availability (if you’re in a beta tester program, updates may come more often)
• 📶 Internet connection stability (use Wi-Fi, not mobile data)

Manual update via Recovery

If the automatic update doesn't work, you can manually install the firmware through Recovery.

1. Download the official firmware for Redmi 9A (model dandelion) from en.miui.com. Choose the Recovery ROM version (file with.zip extension).
2. Rename the file to update.zip and place it in the root directory of the phone’s internal memory.
3. Turn off the phone, then press Power + Volume up to enter Recovery.
4. Select Install update.zip and confirm the installation.

⚠️ Note: If after updating via Recovery phone is stuck on the logo MI, Wait 10 to 15 minutes. Sometimes the first download takes a long time!

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If the sound is gone or the sensor is not working after the firmware, try resetting to factory settings via Recovery (Wipe Data), which often solves driver problems.

3. Fastboot Flashing: For Power Users

Fastboot is a method that works for installing official firmware when other methods don't work, or for recovering a phone after a crash, which requires a computer and knowledge of the command line, and it's important that when you use Fastboot, all the data on your phone will be erased.

3.1. Necessary tools

To run through Fastboot, you will need:

• 🖥️ A computer with installed Xiaomi drivers and ADB/Fastboot (download)
• 📁 Fastboot firmware ROM (tgz or.zip file from Xiaomi)
• 🔧 Archivator for unpacking firmware (for example, 7-Zip WinRAR)

Step-by-step instructions

Follow these steps:

1. Unpack the downloaded firmware into a folder on your computer. flash_all.bat (for Windows or flash_all.sh (for Linux/Mac).
2. Turn off the phone and put it into Fastboot mode, clamping Power + Volume down.
3. Connect your phone to your computer via USB.
4. Open the command prompt in the firmware folder (click Shift + right mouse button → Open the PowerShell window here).
5. Enter the command: fastboot devices Make sure that the phone is determined (should appear its serial number).
6. Run the firmware: flash_all.bat (for Windows or./flash_all.sh (for Linux/Mac).

It takes 5-10 minutes. When it's finished, the phone will automatically restart. If you have a fastboot error: error: Cannot generate image for userdata, try repeating the process or downloading the firmware again.

4. Install custom firmware: LineageOS, Pixel Experience and others

Custom firmware such as LineageOS or Pixel Experience allows you to get a pure Android without the branded MIUI shell, as well as more recent versions of the system. However, installing them requires an unlocked bootloader and can be unwarranted.

Popular custom firmware for Redmi 9A

Installation via TWRP Recovery

To install custom firmware, you will need TWRP Recovery, an alternative recovery menu.

1. Unlock the bootloader (see Section 1).
2. Download TWRP for Redmi 9A (Dandelion model) from twrp.me.
3. Install TWRP via Fastboot: fastboot flash recovery twrp.img fastboot boot twrp.img
4. In TWRP, make a backup of the current firmware (Backup item).
5. Sweep through custom firmware (Install item, select the downloaded.zip file).
6. Clear the cache (Wipe) → Dalvik/ART Cache).

⚠️ Note: Some custom firmware may not support all of Redmi's features 9A, For example, VoLTE or Widevine L1 (viewable HD-Check the reviews on the forums before installing content on Netflix. XDA Developers or 4PDA.

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Custom firmware gives more freedom, but requires an unlocked bootloader and can take away warranties. Official methods are safer, but limited by MIUI functionality.

5. Typical errors and their solutions

Even if you follow the instructions strictly, you can get errors, and let's look at the most common ones and how to fix them.

5.1. Firmware errors in Fastboot

• 🚫 fastboot: error: Failed to boot into fastbootd → Check the cable and port USB, Try another computer.
• 🔄 Waiting for any device → Install Xiaomi drivers or enable debugging by USB.
• 📱 The phone does not turn on after the firmware → Try flashing again via Fastboot or use the Mi Flash Tool.

5.2 Problems after installation of custom firmware

• 🔊 No sound. → Check the AudioFX settings or reflash the kernel.
• 📶 The mobile network is not working → Make sure the firmware supports your region (for example, EEA Europe).
• 🔋 Fast battery discharge → Calibrate the battery (discharge to 0%, then charge to 100% without interruptions).

If the phone stops turning on (brick), try to restore it through EDL-This will require a Qualcomm box or help from a service center.

6.How to return the official firmware after custom

If custom firmware is unstable or you want to return the warranty, you can roll back to the official MIUI.

1. Download Fastboot ROM for your region from Xiaomi’s website.
2. Unpack the archive and launch it. flash_all.bat (sectionally 3).
3. If the phone doesn't boot, use Mi Flash Tool: 1. Install Mi Flash Tool. 2. Select a folder with the unpacked firmware. 3. Connect the phone in Fastboot mode. 4. Press Refresh, then Flash.

Once you return to the official firmware, the bootloader will automatically lock, but the data will be erased. To re-install the custom firmware, you will need to re-unblock the bootloader.

Frequently Asked Questions (FAQ)