Disabling WiFi Probe in MIUI: Protecting Privacy and Traffic

Modern Xiaomi and Redmi smartphones running the shell MIUI or his heir HyperOS, have many background processes that often go unnoticed by the user. One of these features is the mechanism WiFi Probe (or Probe Request), which allows the device to constantly search for available access points, even when Wi-Fi is disabled in the interface. This not only puts unnecessary strain on the battery but also creates a digital footprint that retailers and advertising networks can use to track your location.

Many device owners Xiaomi notice that the battery drains faster, and the router shows an active connection even without any obvious action on the part of the user. Continuous transmission of Probe frames allows the device to be identified by its unique MAC address within a radius of up to 50 meters from the router. Understanding how this technology works and how to limit it is a key step to improving digital hygiene and security on your local network.

In this article, we'll take a detailed look at the technical aspects of the network scanner in Android and MIUI. You'll learn the difference between regular and stealth scanning, and get step-by-step instructions for disabling intrusive features. We'll cover both standard system settings and more in-depth methods via the engineering menu and ADB, which require careful attention.

What is a WiFi Probe Request and why is it needed?

Technology Probe Request is a fundamental part of the IEEE 802.11 standard, which underlies Wi-Fi wireless networks. When you turn on Wi-Fi on your smartphone, the device begins sending out special broadcast frames, asking, "Is there a network I connected to before?" or "What networks are available?" This is necessary for quick reconnection when leaving the coverage area of ​​one access point and entering the coverage area of ​​another, ensuring seamless roaming.

However, in the ecosystem MIUI This mechanism often operates aggressively. The system may continue scanning even when the Wi-Fi slider in the notification shade is turned off. This is done for the "Find Networks" feature or for location services that use Wi-Fi hotspot databases to determine the user's location without GPS enabled. While this speeds up maps, it also creates constant background traffic.

⚠️ Warning: Completely disabling all scanning services may disrupt the Find My Device feature and reduce the accuracy of geolocation in apps that do not use satellite GPS.

There are two main types of scanning: active and passive. Active scanning is initiated by the device (the client) itself, which sends requests. Passive scanning simply listens for signals from routers (beacon frames). WiFi Probe This refers to the active method. In the context of MIUI, the problem is that the system can use randomized MAC addresses for these requests, but the frequency of their sending is sometimes excessive for the average user simply wanting to save battery.

Risk Analysis: Why You Should Limit Scanning

The main risk associated with an active Probe Request is the leakage of metadata about the user's movements. Large shopping malls and airports often use analytics systems that read the MAC addresses of devices passing by their display windows. Even if you don't connect to their Wi-Fi, the mere presence of a Probe Request from your device is a sign of security. Xiaomi is recorded. This allows us to create graphs of attendance and traffic routes.

Furthermore, constantly scanning for networks drains the wireless chip's power. When the signal is weak, the Wi-Fi module increases its transmit power, which leads to overheating and accelerated battery drain. For users who keep Wi-Fi turned on "just in case" but rarely use the internet outside the home, this is a waste of resources.

From a network security perspective, actively broadcasting requests for known networks (for example, "Home_WiFi" or "Office_Guest") can be exploited by attackers. A type of attack called "Evil Twin" occurs when a hacker device overhears your phone's request for a known network and creates a fake copy with the same name. The phone, seeing a familiar name, may attempt to connect automatically, thus falling into a trap.

Basic privacy settings in the MIUI interface

Starting from Android 10 and later versions MIUI 12/13/14Google and Xiaomi have implemented a MAC address randomization feature. This means that when scanning and connecting, the device uses a temporary, random address instead of the permanent factory address. This significantly reduces the possibility of tracking, but does not disable the scanning process itself.

To activate maximum protection at the basic level, you need to go to your Wi-Fi settings. Typically, the path looks like this: Settings → Wi-Fi → Additional settings (or via the gear icon for the current network). Here, it's important to check whether the "Use randomized MAC address" option is enabled. In some firmware versions, this setting is applied globally, while in others, it's specific to each saved network.

Also, in the "Privacy" or "Security" section of MIUI, there's often a toggle that allows network scanning even when Wi-Fi is turned off. It may be called "Wi-Fi Scanning" in the Location Services section. Disabling this setting prevents systems and apps from using Wi-Fi for location services when the main Wi-Fi switch is in the "Off" position.

It's important to distinguish between global settings and access point-specific settings. If you're connected to a home network but want to hide your device from prying eyes, MAC address randomization is essential. However, if your goal is to completely stop Probe frames from being sent, standard switches may not be sufficient, as they only mask the device but don't jam its radio signals.

Hidden features and the Xiaomi engineering menu

For more in-depth customization of the Wi-Fi module behavior in devices Xiaomi There is an engineering menu called CIT (Customer Integration Test). It is accessed via a special code in the Phone app. Enter the command ##6484## or ##4636##The interface may differ depending on the version. MIUI and processor models (Snapdragon or MediaTek).

In the engineering menu, find the Wi-Fi section. It may be called "Single Item Test," "WLAN Test," or "Connectivity." Within this section, you'll often find options for managing the operating mode. For example, you might try finding the "Keep Wi-Fi on during sleep" setting and switching it to "Never." This will force the system to disconnect and stop scanning when the screen locks.

There's also a setting related to "Aggressive Wi-Fi to Cellular Handover." When enabled, the phone will scan for Wi-Fi more frequently to switch from 4G/5G to a faster channel. Disabling this option in the hidden settings (if available in your firmware version) will reduce the frequency of background Probe requests.

⚠️ Warning: Changing settings in the engineering menu may cause instability in the communication module. Write down the original parameter values ​​before changing them so you can restore them to their original state.

Some versions of CIT allow you to view the current MAC address status and even temporarily change it. However, these changes are often temporary and reset after a reboot. For permanent changes, it's better to use the software methods via ADB described below.

What should I do if the engineering menu code doesn't work?

On newer versions of MIUI, access to the full engineering menu may be blocked. Try installing the "Miuikit" app from third-party sources, which unlocks hidden tests, but do so at your own risk.

Disabling via ADB and system commands

The most effective way to control system behavior is to use the Android Debugging Bridge (ADB). This method requires connecting your smartphone to a computer. You'll need to install the ADB drivers on your PC and enable "USB Debugging" in the "Developer Options" menu on your phone (accessed by tapping "MIUI Version" seven times in the "About Phone" section).

Once connected and authorized on the phone's screen, you can send commands to change global Android settings. One key command is to control sleep mode scanning. The command looks like this:

adb shell settings put global wifi_sleep_policy 2

Here is the meaning 2 means "Never keep Wi-Fi on while you sleep." Other meanings: 0 (only when charging) and 1 (Always). Setting the value to 2 forces the Wi-Fi module to go into deep sleep, stopping sending Probe frames, when the screen is off.

You can also try disabling location services scanning via ADB if the standard interface doesn't offer this option. The command can vary, but the following query often works to disable Wi-Fi and Bluetooth location scanning:

adb shell settings put secure location_providers_allowed +gps,-network

This command leaves GPS active, but prevents the system from using networks (Wi-Fi and cell towers) to determine location, which indirectly reduces the activity of communication modules in the background.

Comparison of Wi-Fi activity limiting methods

The choice of method depends on your technical skills and goals. If you simply need to save some battery life, the default settings are sufficient. However, if maximum anonymity is required, you'll need to combine methods. Below is a table comparing the effectiveness of various approaches.

As the table shows, standard methods are only partially effective. RMAC (Randomized MAC) conceals the device's identity but doesn't stop it from broadcasting. ADB and engineering settings allow you to control the radio module's operating mode.

It is worth noting that on new versions Android 13/14 Google has tightened the rules for app access to Wi-Fi scanning. Apps now require special permission, which they must explicitly request. This reduces the number of background scans initiated by third-party software, but MIUI system services may ignore some restrictions for the sake of "optimization."

Frequently Asked Questions (FAQ)

Is it safe to disable Wi-Fi scanning completely?

Yes, it's safe for your hardware. However, you may lose the ability to quickly connect to known networks and smart home functionality if your devices use Wi-Fi for discovery. Geolocation will be less accurate indoors.

Are ADB settings reset after reboot?

Parameters changed through settings put, are usually saved in the Android settings database and survive a reboot. However, a factory reset will return all settings to their default values.

Will this help if I'm using public Wi-Fi?

Yes, especially MAC address randomization. When connecting to public networks, always use "Private Wi-Fi" mode, which automatically generates a random MAC address for each new network.

Does disabling Probe affect Bluetooth performance?

There's no direct impact, as these are different modules. However, in Android, scanning settings are often combined. By disabling Wi-Fi scanning for geolocation, you may also affect Bluetooth scanning, which is important for fitness trackers and watches.

Is it possible to automate this process?

Yes, using automation apps like Tasker or MacroDroid. You can create a script like "If I'm away from home → Disable Wi-Fi and block scanning." This is more effective than manual control.