How to flash Xiaomi Redmi 9S: official and custom methods

Why do you want to use the Redmi 9S and what are the risks?

The firmware of the Xiaomi Redmi 9S smartphone (codename curtana) may be needed for various reasons: from solving software failures to installing a fresh version of MIUI or custom firmware such as LineageOS. However, the process requires care - an error at the stage of unlocking the bootloader or choosing the wrong version of the software can turn the device into a "brick".

Official updates via MIUI Updater are usually safe, but not always available to all regions. Alternative methods, such as firmware via Fastboot or Recovery, provide more control, but also increase risks. For example, incompatible firmware for the Redmi 9A model (which looks like the 9S) will lead to system failure. In this article, we will analyze all the current methods, taking into account the features of the Redmi 9S 2026.

Before you start, check out the current version of MIUI in Settings → About Phone → MIUI Version. If it is older than 12.5.3, we recommend that you update officially – this will eliminate the majority of bugs without risks. For enthusiasts who want to install Global ROM on the Chinese version or custom software, read on.

Preparation for firmware: what to do before the start

Regardless of the method chosen, preparing the device reduces the chances of errors. Start with a backup of important data: the firmware erases internal memory (except for the microSD card). Use Mi Cloud or third-party tools like Titanium Backup (requires root).

Next, check the battery charge - it must be at least 60%. When discharged during firmware through Fastboot, the device can hang on the Mi logo.

• 🔌 Cable USB Type-C (original or certified – cheap cables often cause connection errors).
• 💻 Windows computer 10/11 (for Fastboot or Mac/Linux (for ADB).
• 📥 Firmware for your model (download only from the official Xiaomi website or verified sources of the type) XDA Developers).
• 🔓 Unlocked bootloader (required for custom firmware).

⚠️ Attention: If your Redmi is 9S purchased in China, by Global ROM If you don't unlock the bootloader, it will lead to the device's blink. → Additionally. → Region.

To install the firmware via Fastboot, additionally install:

• 🛠️ Platform Tools (includes fastboot and adb).
• 🔧 Xiaomi Drivers (download from Xiaomi Flash Tool).

Method 1: Officially Updated with MIUI Updater

The safest way is to upgrade through the built-in System Update app. It is suitable for installing the latest versions of MIUI without losing data. Open Settings → About Phone → Update MIUI and click Check Updates.

If the update is available, the system will offer to download the package (.zip file is about 2-3 GB).

1. Connect to Wi-Fi (update via mobile Internet may be interrupted).
2. Click Set and wait for the reboot.
3. Do not interrupt the process – the device will restart 2-3 times.

If the update doesn’t come automatically, try:

• 🔄 Switch to another region in settings (for example, India often gets updates earlier).
• 📡 Use it. VPN servers in Europe or Asia.
• ⏳ Wait 1-2 weeks – Xiaomi rolls out updates gradually.

⚠️ Warning: If the device has been stuck on the Mi logo for more than 10 minutes after the update, reset via Recovery (click Power). + Loudness up).

💡

Officially OTA-Updates do not require unlocking the bootloader and retain the Xiaomi warranty.

Method 2: Fastboot (Mi Flash Tool)

This method is used to install full firmware (for example, when switching from China ROM to Global) or restore the device after a failure.

• 🖥️ Computer with Mi Flash Tool and drivers installed.
• 📦 Firmware in.tgz format (download from the official website by selecting the Redmi model) 9S (curtana)).
• 🔓 Unlocked boot loader (instruction below).

Firmware steps:

1. Unpack the firmware in a folder without Cyrillic characters (for example, C:\curtana_global).
2. Turn off the phone and press Power + Volume down to enter the Fastboot (a hare in a hat-eared hat will appear).
3. Connect the device to your PC and start MiFlash.exe.
4. In the program, click Select, specify the folder with the firmware, then Refresh (should appear). COM-port).
5. Select Clean All or Clean All and Lock (if you want to lock the bootloader after you have been firmware).
6. Press Flash and wait until it is completed (the process will take 5-10 minutes).

Once the firmware is successful, the device will automatically restart. The first run can take up to 15 minutes - don't interrupt it.

Download the correct firmware version for curtana|

Install Mi Flash Tool and drivers |

Unlock the loader (if required) |

Charge your phone at least 60% |

Create a data backup

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Method 3: Install custom firmware (TWRP + LineageOS)

For enthusiasts looking to install LineageOS, Pixel Experience or other custom firmware, an unlocked bootloader and TWRP Recovery will be required.There is no official TWRP for the Redmi 9S, but there are unofficial builds from the XDA community.

Procedure:

1. Download: 📱 Informal TWRP for curtana. 📦 Custom firmware (e.g. LineageOS 20 for curtana). 🔑 Magisk (if you need root).

Fastboot

fastboot flash recovery twrp-3.7.0_curtana.img


fastboot reboot recovery

TWRP

Wipe → Format Data

yes

Magisk

Install

Reboot to the system.

The first launch of custom firmware can take up to 20 minutes. If the device is getting stuck on the screensaver, repeat the installation by pre-formatting the System partition.

⚠️ Attention: Castom firmware disables encryption by default. If you need encryption, install OrangeFox Recovery instead of TWRP.

Unlocking the bootloader: step-by-step instruction 2026

To install custom software or firmware, you need to unlock the bootloader. Xiaomi allows this to be done officially, but the process takes up to 7 days (due to account verification).

Steps:

1. Link your Mi Account to your device in Settings → Xiaomi Account.
2. Go to Settings → About Phone → MIUI version and tap 7 times on the Build Number to activate Developer Mode.
3. Back to Settings → Additionally. → For developers and include: 🔓 Unlocking OEM (It may not be available on some versions. MIUI). 🔌 Debugging by USB.

Mi Unlock Tool

Food + Volume Down

Fastboot

Mi Unlock Tool

Unlock

Once unlocked, the bootloader will remain open, allowing any firmware to be installed, but this resets the device to factory settings and can void the warranty.

1. Use another. USB-cable.

2. disable the antivirus on the PC.

3. Repeat the attempt after 24 hours (sometimes Xiaomi servers are overloaded).-->

Frequent mistakes and their solutions

Even if you follow the instructions, you can get errors, and let's look at the typical problems and how to fix them:

If the error is not listed in the table, look for its code in the Mi Flash Tool error database or ask a question on XDA Developers indicating the curtana model.

FAQ: Answers to popular questions