How to flash Xiaomi Redmi 3S: official and custom firmware

Xiaomi Redmi 3S is the legendary budget smartphone of 2016, which is still used by many users.However, over time, official support for the device stops and older versions of MIUI stop receiving security updates. The phone’s firmware can solve performance problems, add new features or even “resurrection” the device after a software failure.

In this guide, we will discuss all the current ways to implement Redmi 3S (codename land): from the official update via MIUI Updater to install custom firmware via TWRP and Fastboot. Special attention will be paid to unlocking the bootloader, a key step without which most methods simply will not work, and you will learn how to avoid brick (brick) – a state when the phone stops turning on due to incorrect firmware.

Preparation for firmware: what you need to know before starting

Xiaomi Redmi 3S firmware is a simple process, but it requires care. The first thing to do is to save all the important data. Even if you plan to upgrade without resetting, there is always a risk of losing information. Use Mi Cloud, Google Photos or physical copying on your PC for backup:

• 📱 Contacts (export to) VCF-file)
• 📷 Photos and videos (especially from the folder) DCIM)
• 📄 Documents and downloads
• 🎮 Save games (if you play Mobile Legends, PUBG Mobile and others.)

Second, check the current MIUI and the phone model. Go to Settings → About the phone.

• 📋 Version. MIUI (for example, MIUI Global 12.5.1 Stable)
• 🔢 Assembly number (e.g, V12.5.1.0.LALMIXM)
• 📱 Device code name (land for Redmi) 3S)

⚠️ Attention: If your Redmi is 3S purchased in China (domestic version), firmware global version MIUI It can block the network! Check the model in Settings → The phone. → Model. If it says 2016030 or 2016031, it's the Chinese version.

The third step is to charge the battery, make sure it's at least 60 percent, and it can take 10 to 40 minutes to run out of power, and if the phone dies in the process, it can't be recovered without a service center.

Method 1: Officially Update with MIUI Updater (without unlocking)

The easiest and safest method is to upgrade through the built-in MIUI Updater app, which is suitable if:

• 🔄 You want to upgrade to the latest official version. MIUI
• 🔓 Phone boot loader locked (standard state)
• 📶 You have a stable Wi-Fi connection

Instructions:

1. Open the MIUI Updater app on your phone.
2. Click on the three dots in the top right corner and select Select Service Pack.
3. If an update is available, download it (file weight ~1.5–2 GB).
4. After downloading, click Reboot and Update.

If there are no updates, but you know that your model has a new version, you can download the firmware manually from the official MIUI Downloads website. Choose files marked Recovery (not Fastboot!) for this method.

⚠️ Warning: Do not interrupt the upgrade process, even if the phone is long hanging on the Mi logo. The average installation time is 5-15 minutes. If after 20 minutes nothing happens, try forcibly restart the phone (clip the power supply). + Volume up for 10 seconds).

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The official update via MIUI Updater does not require unlocking the bootloader and saves all user data.

Method 2: Firmware through Recovery (TWRP) – for custom firmware

If you want to install informal firmware (like LineageOS, Pixel Experience, or HavocOS), you’ll need TWRP Recovery, a custom recovery technique that’s also useful if you don’t install an official update.

Steps:

1. Unlock the bootloader (instructions in the next section).
2. Download TWRP for Redmi 3S (Look for the land version) from twrp.me.
3. Install TWRP via Fastboot (TWRP command: fastboot flash recovery twrp.img).
4. Upload the phone to TWRP (clip Power + Volume up).
5. Make a backup of the current firmware (Backup option in TWRP).
6. Sweep the custom firmware (.zip file) through Install.

The following are the best custom firmware for Redmi 3S:

⚠️ Attention: Castom firmware may contain bugs! Before installing, check the reviews on forums (for example, 4PDA Some firmware does not support VoLTE (calls over the phone). 4G) Or have problems with the camera.

Download firmware (.zip) and GApps (if necessary)|Download TWRP for Redmi 3S (land)|Unlock the loader|Backup in. TWRP|Charge the phone to 70%+-->

Method 3: Fastboot firmware for official and custom ROMs

Fastboot is a boot mode that allows you to flash your phone through your computer, and it's a method that's suitable for:

• 🔧 Installation of official firmware (if the phone is not turned on)
• 📦 Custom firmware ROM (if TWRP doesn't work)
• 🔄 Recovery after a failure (for example, after a failed firmware)

Instructions:

1. Download the Mi Flash Tool from Xiaomi’s official website.
2. Download the firmware in.tgz format (for Fastboot) from MIUI Downloads.
3. Unpack the archive into a folder without Cyrillic characters (e.g., C:\MIUI\land).
4. Turn off the phone and press Volume Down + Power to log into the Fastboot.
5. Connect your phone to your PC and start the Mi Flash Tool.
6. Select the firmware folder and press Refresh (should appear) COM-port).
7. Press Flash and wait until it is finished (10-15 minutes).

If the Mi Flash Tool is not loading, install Qualcomm drivers manually or use an alternative Fastboot Enhance utility.

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If the phone is stuck on the Mi logo after Fastboot, try resetting the settings via Recovery (click Power + Volume up and select Wipe Data).

How to unlock the bootloader on Xiaomi Redmi 3S

Without unlocking the bootloader, you won’t be able to flash custom Recovery or unofficial firmware. Xiaomi locks the bootloader on all devices, but it can be unlocked officially through the Mi Unlock Tool.

Steps:

1. Link your Mi Account to your phone: go to Settings → Mi Account → Sync and turn it on.
2. Activate debugging via USB: Settings → About Phone → MIUI version (click 7 times), then Additional → For Developers → Debugging via USB.
3. Download Mi Unlock Tool from the official website.
4. Launch the utility, log in to your Mi Account and connect your phone in Fastboot mode.
5. Press Unlock and wait until it is completed (usually takes 3-5 minutes).

⚠️ Note: Once the bootloader is unlocked, all data on the phone will be erased, and Xiaomi can block the unlock for 7 to 30 days if you recently linked an account.

If the Mi Unlock Tool is running a "Couldn't unlock" error, try it.

• 🔌 Use the other USB-port (preferably) USB 2.0)
• 🖥️ Launching the utility on behalf of the administrator
• 🔄 Restart your phone and PC
• 📡 Connect to another network (sometimes the lock is linked to the IP)

Frequent Firmware Errors Redmi 3S and Their Solutions

Even with strict adherence to the instructions, errors can occur, and here are the most common problems and ways to correct them:

If your phone has turned into a brick (it doesn't turn on, it doesn't respond to buttons), don't panic. In 90% of cases, it can be recovered through a phone. EDL-The Emergency Download Mode is required:

• 🖥️ Computer with Qualcomm 9008 drivers installed
• 🔌 Cable USB (better-than-original)
• 📦 Firmware in.mbn format for EDL
• 🛠️ Mi Flash Pro or QFil

Instructions for EDL recovery can be found on 4PDA or XDA-Developers. Note: This method requires experience and can be dangerous to the device if used improperly.

How to return the official firmware after custom

If you’ve been experimenting with custom firmware but want to return to the official MIUI, do the following:

1. Download the latest stable firmware for Redmi 3S from MIUI Downloads (choose Fastboot or Recovery).
2. If you have TWRP installed, run the official firmware through Install (.zip file).
3. If TWRP doesn’t work, use Fastboot (instruction in Section 3).
4. After the firmware, reset the settings (Wipe Data) to avoid conflicts.

Important: When you return to the official firmware, the bootloader will automatically lock, and if you plan to install custom ROMs again, you will have to unlock them again.

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You can return to the official firmware at any time, but this will block the bootloader and delete all data.

FAQ: Answers to Frequent Questions