Xiaomi Mi Note 3 firmware via Fastboot: a complete guide with unlocking the bootloader

Xiaomi Mi Note 3 is the iconic smartphone of 2017, which is still popular today due to the powerful hardware and the ability to install custom firmware. However, over time, official support for MIUI ceases, and users face slowdowns, bugs or the desire to switch to a pure Android. Fastboot firmware is one of the most reliable ways to update or restore the device, but the process requires accuracy and understanding of nuances.

In this article, you will find step-by-step instructions on how to run the Mi Note 3 through Fastboot, including unlocking the bootloader, choosing the right firmware version, and solving typical bugs. We have taken into account all the changes in 2026: updated Xiaomi unlock requirements, current versions of tools, and features of working with MiFlash. If you have never flashed a smartphone before, do not worry: the manual is designed for beginners, but also contains advanced tips for experienced users.

1. Firmware Preparation: What to Do Before Starting

Fastboot firmware is a process that can both revive your Mi Note 3 and turn it into a brick if you neglect the preparation. First and most important, unlocking the bootloader erases all data from the device without any recovery capability. So start with backup.

List of mandatory actions before the firmware:

• 📱 Save data: contacts, photos, messages (use Mi Cloud, Google Account or local copying on PC).
• 🔋 Charge the battery to at least 60% – this will prevent a sudden shutdown during the process.
• 🖥️ Install drivers: download Mi PC Suite or Qualcomm drivers for Fastboot.
• 🔗 Prepare the cable: use the original USB-Xiaomi cable (cheap analogues can cause data transmission errors).

Also check your device model in settings (Settings) → The phone. → Model. Mi Note. 3 It has two versions: jason (global version) and jason_china (Installing firmware not for your model will cause the device to fail!

⚠️ Note: If your Mi Note 3 was purchased with rooted firmware or customized recavery (TWRP), The process of unlocking the bootloader may be different, in which case, first go back to the stock firmware via Fastboot.

2. Unlock the bootloader: how to get permission from Xiaomi

Xiaomi blocks the bootloader on all devices, so before you run through Fastboot, it needs to be unlocked. In 2026, the process became stricter: now you need to link your Mi Account and wait for confirmation (usually 3-7 days).

1. Link your Mi Account to your device: Go to Settings → Xiaomi Account → Mi Cloud. Enable sync and make sure the device is linked to your account.
2. Send an unlock request: Download the Mi Unlock Tool (2026 version). Launch the tool, log in to your Mi Account and follow the instructions. Connect your phone in Fastboot mode (click Volume Down + Power When the device is off).

After sending a request, Xiaomi will check your account history, if the device was tied less than 7 days ago, you will be refused, and unlocking can be refused if:

• 🚫 New account (less than 30 days from the date of registration).
• 🚫 The device was unlocked earlier by another account.
• 🚫 There is an unofficial firmware on the phone.

⚠️ Note: If the Mi Unlock Tool shows a “Couldn’t unlock” error even after waiting, try: Use another Windows PC 10/11 (on Linux/Mac Disable the antivirus and firewall, re-assign the Mi Account on your phone.

Linked to the Mi Account to the device|On. OEM-unlock|Debugging is on. USB|Qualcomm drivers installed|Phone's 60-charged%+-->

3. firmware selection: official MIUI vs custom builds

Once you unlock the bootloader, you have to choose the firmware. You have two basic options:

Where to download the firmware for Mi Note 3:

• 🔹 Officially MIUI: Xiaomi official website (select the version for jason or jason_china). Xiaomi Firmware Updater (up-to-date builds with patches).
• 🔹 Custom firmware: XDA Developers (tweet for Mi Note 3) LineageOS (unofficial builds for jason).

For beginners, we recommend starting with the official firmware version of MIUI 12.5 or MIUI 14 (the latter stable for the Mi Note 3). Castom firmware requires additional manipulations (install TWRP, partition formatting), so it is better to leave them for later.

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If you download firmware from Xiaomi Firmware Updater, choose files marked Fastboot (not Recovery!). These have the.tgz extension and contain all the necessary scripts for firmware through MiFlash.

4. Install firmware through MiFlash: step-by-step instructions

Now, to the most important stage, Fastboot, you'll need:

• 🖥️ Windows PC 10/11 (on macOS/Linux MiFlash is not working).
• 📦 Unpacked firmware in.tgz format (remove it to a folder without Cyrillic characters!).
• 🔌 Original. USB-cable.
• 🛠️ MiFlash utility (version 2022 or newer).

Instructions:

1. Turn off your phone and turn it into Fastboot: Press the "Loudness Down" + "Power" buttons for 10 seconds. A hare in a hat-eared hat (Fastboot logo) will appear on the screen.
2. Connect your phone to your PC and check for recognition: In the command line (Win + R → cmd) type: fastboot devices If the device is displayed (for example, abc12345 fastboot) – the drivers are installed correctly.
3. Run MiFlash: Press Select and select the folder with the unpacked firmware. At the bottom, select Clean All or Clean All and Lock. + Press Refresh, your device should appear in the list. Click Flash and wait until it is completed (usually 5-10 minutes).

The firmware process is accompanied by a green streak of progress in MiFlash. Upon completion, the phone will automatically restart. The first launch can take up to 15 minutes - don't interrupt it!

⚠️ Note: If MiFlash gives a critical partition flashing error is not allowed, it means: You are trying to flash firmware not for your model (Jason vs. jason_china). Or use an outdated version of the utility (download MiFlash). 2022+). Solution: Check the device model and firmware version.

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Always use clean all mode when running through Fastboot, which ensures that there is no conflict between old and new system files.

5. Typical errors and their solutions

Even with the instructions followed accurately, errors can occur, and here are the most common problems when running the Mi Note 3 firmware via Fastboot and how to fix them:

If you load your phone after you run the firmware, but you have a glitch (like a sensor or camera doesn't work), you probably have an incompatible firmware.

1. Download another firmware version (for example, instead of MIUI 14 try MIUI 12.5).
2. Repeat the firmware through Fastboot with a full clean (clean all).
3. If the problem persists, check the integrity of the downloaded archive (it may be damaged).

6. firmware custom ROM: LineageOS, Pixel Experience and others

If the official MIUI doesn't suit you, you can install custom firmware. For the Mi Note 3 (jason), it's popular:

• 📱 LineageOS – pure Android with long-term support.
• 📱 Pixel Experience – firmware with interface and Google Pixel chips.
• 📱 crDroid – Balance between Stability and Customization.
• 📱 Havoc-OS – for lovers of fine tuning.

The process of installing custom firmware differs from the official one and requires the pre-installing of TWRP (Castom Recovery).

1. Install. TWRP: Download the current version for Mi Note 3 official website TWRP Fastboot: Fastboot Flash Recovery twrp-3.7.0_jason.img fastboot boot twrp-3.7.0_jason.img
2. Backup in TWRP (Boot, System, Data) sections.
3. Sweep the firmware: Copy ZIP-a firmware file on the phone. TWRP Choose Install → Choose. ZIP → Swipe to Confirm Flash.

Squeeze Gapps.

Download the appropriate package (e.g. OpenGapps for ARM64, Android 11) and install it similarly to firmware.

After installing custom firmware, additional configuration may be required:

• 🔧 SELinux setting (if the firmware is giving security errors).
• 🔧 Battery calibration (through TWRP or the AccuBattery application).
• 🔧 Installation of the kernel or mods (e.g. Magisk for root rights).

⚠️ Note: Castom firmware may not support some features of the Mi Note 3: 🚫 IR Blaster (infrared port) often does not work on unofficial ROM. 🚫 The camera may have artifacts (fixed by GCam installation). 🚫 NFC You may need additional patches. Read forum reviews before installing (XDA, 4PDA).

7. Post-Firmware Optimization: How to Speed Up Work

After successful firmware (especially if you switched to custom firmware), it is recommended to perform several steps to optimize the Mi Note 3:

1. Disable unnecessary services: Go to Settings → Apps → All apps. Disable or uninstall pre-installed programs (Mi Browser, Mi Music, Mi Video).
2. Set up autoboot: Use the App Quarantine app or built-in firmware settings to limit background activity.
3. Optimize the battery: Turn on Battery → Energy Saving. Turn off the Aodai (Always On Display) if you don't need it.

Update the modem and core

Download current files for Mi Note 3 with XDA and stream through TWRP.

If you have stitched the official MIUI, but the phone began to slow down, try:

• 🔄 Reset the settings to factory (Settings) → Additionally. → Recovery and discharge).
• 🔄 Disable animation: Enable Developer Mode and install: Windows animation = 0.5x Animation of transitions = 0.5x Duration of the animator = 0.5x

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To speed up the Mi Note 3 on custom firmware, install the FrancoKernel or Perseus kernel – they are optimized for the Snapdragon 660 and reduce heating.

FAQ: Answers to Frequent Questions