Debugging by USB on Xiaomi Redmi 9T: how to turn on in 5 minutes (with photo)

USB debugging mode on Xiaomi Redmi 9T is a hidden feature that gives access to advanced smartphone features: custom firmware installation, work with ADB, backup through the computer and even unlock the bootloader. Without it, you can not use tools like Fastboot or Mi Flash Tool, and many backup applications (for example, Titanium Backup) simply refuse to work.

But the manufacturer hides this option deep in the menu — it's not in the standard settings. To activate debugging, you first need to unlock the developer mode, and then turn on the function itself. On Redmi 9T (model M2010J19SG), the process is nuanced because of the features of the MIUI shell. In this article, a step-by-step instruction with all the pitfalls, relevant for the MIUI firmware versions 12.5, 13 and 14.

⚠️ Important: Including debugging by USB Reduces the security of the device: Do not connect your smartphone to unverified computers and do not install unknown.apk files in this mode.

1.Preparation: What will be needed before turning on debugging

Before you start setting up, make sure you have everything you need, and missing at least one of the items can cause you to crash or not be able to complete the process.

• 📱 Smartphone Xiaomi Redmi 9T with a battery charge of at least 50% (at a low charge, the system can block access to the developer settings).
• 🔌 USB-cable (preferably original from Xiaomi – cheap cables often do not support data transfer).

If you plan to use debugging only to install applications through ADB (like Google Camera), the computer is optional, but you will need it to unlock the bootloader or firmware.

⚠️ Note: On some versions MIUI 14 after turning on debugging by USB You may get a notification of "unauthorized access." That's okay -- just confirm the action on your smartphone screen.

2. How to unlock developer mode on Redmi 9T

By default, the “Developers For” option is hidden in Xiaomi’s settings, and to activate it, you need to perform a simple but not obvious manipulation.

1. Open the Settings app (the gear icon on the home screen).
2. Scroll down and select the About Phone section.
3. Find the line MIUI version and tap it 7 times in a row, after 3-4 clicks will pop up the notification: "You're almost there!".
4. Keep pressing until you see the message: You became a developer!

Now, a new section will appear in the main settings menu — Additional → For Developers. On some firmware, it may be called Advanced Settings → Developer Settings.

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If after 7 taps nothing happens, check if the smartphone is installed child mode or parental control – they block access to hidden settings.

3. Step-by-step instruction: enable debugging over USB

Once the developer mode is unlocked, there are only a few steps left to take. Follow the instructions carefully, and incorrect actions can cause the system to crash.

1. Return to the main Settings menu and open the Additional → For Developers section (or Advanced Settings → Developer Settings).
2. Scroll the list to the Debugging block and find the Debugging switch over USB.
3. Activate the slider, you'll see a risk warning. Press OK.
4. The system can request PIN-Mi Account code or password (if linked) Enter it.

Now, when you connect to your computer, your smartphone will ask for debugging permission. Always check the name of the device in the confirmation window, because fraudsters can swap it for data theft.

4. Connection to a computer and check of operation

To make sure that USB debugging works correctly, run a test connection.This step is a must if you plan to use ADB or Fastboot.

1. Connect Redmi 9T to your PC with the original cable.
2. On the screen of the smartphone will appear the request: Allow debugging over USB?. Check Always allow from this computer and click Allow.
3. On your computer, open the command line (Win + R → enter cmd) and execute the command: adb devices
4. If you see a serial number (e.g., 1234abcd device) in the answer, the debugging works. If not, check the drivers or cable.

⚠️ Attention: On Windows 10/11 Sometimes you need to manually install the Xiaomi driver. ADB Download it from the official Mi Community website.

5. Frequent mistakes and how to avoid them

Even with the correct instructions, users face problems, and here are the most common ones and the ways to solve them:

• 🔄 "Developer Mode Disappears After Update" — MIUI Sometimes it resets hidden settings. Repeat the steps from Section 2.
• 🔌 "Computer Can't See Phone - Check if PC is on File Transfer (MTP) smartphone-light.
• 🔒 "Asks for the Mi Account password — if you forget the password, restore it on the Xiaomi website.
• ⚡ "Phone overheats when debugging - it's normal for long sessions ADB. Use the original RAM and avoid direct sunlight.

6.Security: How to protect data when debugging is enabled

Debugging over USB opens up access to your smartphone's system files, which can be dangerous.

• 🛡️ Connect only to trusted PCs – public computers (in Internet cafes, universities) may contain malware.
• 🔑 Turn off debugging after use - go back to Settings → For developers and deactivate the slider.
• 📱 Use a screen lock – without PIN-Any user's fingerprint or code can access the data through ADB.
• 🔄 Regularly update the firmware in new versions MIUI Closing vulnerabilities associated with debugging.

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Never connect a smartphone with USB debugging enabled to other people’s charging stations (such as airports), which can be used by attackers to steal data through BadUSB attacks.

7. Alternative ways to enable debugging (if the standard one doesn't work)

If for some reason you can’t activate debugging through the menu (for example, your smartphone is locked or the developer menu is missing), try these methods:

Method 1: Through ADB (if USB-The debugging has already been included)

If you previously enabled debugging, but it disappeared after reset, you can return it with the command:

adb shell settings put global development_settings_enabled 1


adb shell am start -n com.android.settings/.DevelopmentSettings

Method 2: Using the Mi Unlock Tool (only to unlock the bootloader)

The official utility from Xiaomi can automatically activate debugging when you connect to a PC. Download it from the Mi Unlock website.

⚠️ Note: Using informal methods (e.g. via Fastboot) can result in a Mi Account being blocked or a loss of warranty.

FAQ: Answers to Frequent Questions