How to flash Xiaomi Mi Router 3: official and custom firmware

Xiaomi Mi Router 3 is a popular router with good price-to-function ratio, but its standard firmware often limits the user’s ability. The firmware of alternative software (such as OpenWRT or Padavan) allows you to unlock the full potential of the device, from advanced network settings to support for VPN and adblockers. However, the firmware process requires accuracy – a bug can turn the router into a “brick”.

In this guide, we will discuss all the steps from preparing and unlocking the bootloader to installing custom firmware via SSH or the web interface. Separately, we will focus on choosing the right version of the software, backing up settings and typical problems (for example, the “Invalid firmware” error). If you are a beginner, we recommend starting with official firmware from Xiaomi – they are safer, but less functional.

1. Firmware Preparation: What You Need to Know Before You Start

Mi Router 3 firmware is an irreversible process when it comes to custom solutions. Even official updates over MiWiFi sometimes cause failures, so preparation is critical.

• 🔌 Stable power: Use an uninterruptible power supply (UPS) or a full-charging laptop. A power outage while running a firmware is almost guaranteed to kill the router.
• 📡 Network cable: connect the router to the PC by wire (Wi-Fi off!) Use the LAN1 port, which is more stable than the others.
• 💾 Backup: Save current settings via MiWiFi → Settings → Backup. This will come in handy if you need to restore configuration after the firmware.
• 🔍 Checking the model: on the sticker under the router should be an inscription R3 or R3G Firmware for Mi Router 3C or 4A They won't.

Critical detail: Routers with firmware older than 2018 may have a locked bootloader, which will require additional unlocking through exploit (see Section 3). If your router is purchased after 2020, chances are that the bootloader has already been unlocked by the manufacturer.

2. Selection of firmware: official vs custom

The choice of firmware depends on the capabilities of the router and the risks of installation.

For most users, the best choice is Padavan. This firmware keeps the setup simple, but adds key features: WireGuard support, DNS-over-HTTPS setup, and Xiaomi restrictions removal. If you want maximum features (like installing a Pi-hole to block ads), choose OpenWRT, but be prepared for manual setup.

Where to download firmware? Official versions are from miwifi.com (requires a Xiaomi account).

• 🌐 OpenWRT for Mi Router 3
• 🌐 Padavan on 4PDA (look for topics marked R3)

Attention:

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Before downloading, check the hash of the firmware file (MD5 or SHA256) using the utility certutil -hashfile name file MD5 in the Windows command line.

3. Unlock the loader (if required)

Mi Router 3 routers released before 2019 often have a locked bootloader, which means that installing custom firmware through standard methods is impossible - it will require bypassing protection.

1. Getting SSH- access through a vulnerability in the web interface.
2. Sending a command to unlock the loader.

For this:

1. Connect the router to the PC via cable and log into the control panel at 192.168.31.1.
2. Go to Settings. → Additionally. → SSH and enable access (if you have an option). If you don't have one, use exploit:

curl -s http://192.168.31.1/cgi-bin/luci/;stok=$(grep -oP 'stok=\K[^&]+' /tmp/luci-indexcache)/api-xqsystem/set_ssh_close?enable=1

Then, use SSH with root login and password (empty or admin by default).

nvram set boot_wait=on


nvram set uart_en=1




nvram commit




reboot

⚠️ Warning: If the router doesn't respond after the reboot, wait 5-10 minutes. A new bootloader may be initiating. Don't turn off the power!

4. firmware via web interface (for official and some custom firmware)

The easiest way is to upgrade through the standard MiWiFi interface, which is suitable for official firmware and some modified ones (for example, Padavan with Xiaomi's signature).

Download firmware in.bin| Disable antivirus and firewall | Connect to the router via cable |Reset settings to factory (optional)

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1. Go to the control panel at 192.168.31.1 (login / password - admin/admin, if not changed).
2. Go to Settings → Update firmware.
3. Click Select File and download the downloaded.bin file.
4. Wait for the file to be checked (it can take 1-2 minutes). If an error occurs "Invalid firmware", then the firmware is not signed by Xiaomi - use alternative methods (SSH or TFTP).
5. Press Update and do not turn off power for 5-7 minutes (the router will restart automatically).

After updating, the router can:

• 🔄 Rebooting 2-3 times is normal.
• 🚫 Do not respond to ping for 3-5 minutes - wait.
• ⚠️ Hang in the "Applying settings" step, in which case the reset button will help.

Important: If the router doesn't give away Wi-Fi after Padavan firmware, check the settings in Network → Wireless. Sometimes you need to manually specify the region (Country Code) and channel.

5. SSH firmware (for OpenWRT and unofficial builds)

If the web interface refuses to accept firmware, use SSH. This is a universal method, but requires care.

• 🖥️ A computer with Windows/Linux/macOS and a client SSH (e.g., PuTTY or embedded Terminal).
• 📁 A firmware in.bin or.trx format loaded to the root of the C: disk (for convenience).
• 🔌 Connect via cable (Wi-Fi off!)

Instructions:

1. Connect to SSH: ssh root@192.168.31.1 The default password is admin (or blank if you haven't changed it).
2. Check the current firmware: cat /proc/mtd nvram get firmware_version
3. Copy the firmware to the router (if the file is on PC): scp C:\firmware.bin root@192.168.31.1:/tmp
4. Install firmware: mtd -r write /tmp/firmware.bin firmware For OpenWRT: sysupgrade -n /tmp/firmware.bin

⚠️ Warning: If the error "Could not open mtd device" appears after mtd write, then the firmware partition is blocked. Try the alternative command: dd if=/tmp/firmware.bin of=/dev/mtdblock2 But this is risky - if the error occurs, the router may stop loading!

After a successful firmware run, the router will restart. If it doesn't respond after 10 minutes, try:

• 🔌 Turn off power for 30 seconds and turn on again.
• 🔍 Check IP- the address of the router on the network (may change to 192.168.1.1).
• 🛠️ Use emergency mode (see section 6).

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SSH firmware is the most reliable way to openwrt, but requires command knowledge. If you're not sure, start with padavan through the web interface.

6.Router Restore after Failed Firmware

If the router is no longer responding, don't panic. In 90% of cases, it can be restored via Emergency Mode (TFTP) or UART. Let's look at both.

Method 1: Recovery via TFTP (for soft brick)

If the router flashes orange or does not load, but responds to power:

1. Install a TFTP- server on your PC (e.g., Tftpd64).
2. Place the miwifi_r3_firmware_*.bin firmware in the server folder (usually C:\TFTP-Root).
3. Configure your PC network card to static IP 192.168.31.100 with a 255.255.255.0 mask.
4. Turn off the router, press the Reset button and turn on the power. Hold the button for 10-15 seconds until the indicator flashes quickly.
5. The router will automatically download the firmware from the TFTP- server (wait for 3-5 minutes).

Method 2: UART connection (for hard brick)

If the router is not showing signs of life, you will need a soldering iron and a USB-UART adapter (for example, CP2102).

• 🔧 Salt contacts to the router board (see diagram for Mi Router 3 on 4PDA).
• 🖥️ Connect the adapter to the PC and open PuTTY (speed 115200 bits/s).
• 🔄 Turn on the router – the bootloader output (U-Boot) should appear in the logs.
• 📤 Interrupt Enter key loading and enter firmware commands via TFTP: setenv serverip 192.168.31.100 setenv ipaddr 192.168.31.1 tftpboot 0x80060000 miwifi_r3_firmware.bin erase 0x9f020000 +0x7a0000 erase 0x9f020000 +0x80060000 0x9f020000 0x7a0000 bootm 0x9f020000

⚠️ Warning: Soldering requires experience! Incorrect connection UART can damage the board. If you're not sure, contact the service center.

7.Setting up the router after firmware

Once the firmware is successful, the router needs to be reconfigured.

For Padavan:

• 🌐 The web interface will be available at 192.168.1.1 (login/password — admin/admin).
• 🔒 First, change your password in Administration → System.
• 📶 Set up Wi-Fi in Network → Wireless (select a channel with minimal interference).
• 🛡️ Enable firewall and turn off remote access in Administration → Remote Access.

For OpenWRT:

• 🐧 The LuCI interface is available on 192.168.1.1 (password not set by default).
• 📦 Install the required packages through System → Software (e.g. luci-app-sqm for QoS).
• 🔗 Set up a WAN- Network → Interfaces connection (select PPPoE or DHCP protocol).
• 🔄 Update the packet list: opkg update opkg upgrade

Optimization recommendations:

• 📈 For stable operation, disable IPv6 if your provider does not support it.
• 🔋 Reduce Wi-Fi power to 70% in settings to reduce the load on the chip.
• 🕒 Set up an automatic router reboot once a day (in System → Scheduled Tasks).

FAQ: Frequent questions about the firmware Xiaomi Mi Router 3