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Starting in Android 8.0, Android devices use randomized MAC addresses when
probing for new networks while not associated with a network. In
Android 9, you can enable a developer option (it's
disabled by default) to cause the device to use a randomized MAC address
when connecting to a Wi-Fi network.
In Android 10, MAC randomization is enabled by default
for client mode, SoftAp, and Wi-Fi Direct.
MAC randomization prevents listeners from using MAC addresses to build a history
of device activity, thus increasing user privacy.
Additionally, MAC addresses are randomized as part of
Wi-Fi Aware and
Wi-Fi RTT operations.
Work with a Wi-Fi chip vendor to implement the following HAL methods:
IWifiStaIface#setMacAddress: Configures the MAC address of the
interface. The default implementation brings the interface down, changes
the MAC address, and brings the interface back up.
IWifiStaIface#getFactoryMacAddress: Gets the factory MAC of wlan0
using an ioctl call.
ISupplicantP2pIface#setMacRandomization: Sets P2P MAC randomization
on/off in the supplicant.
Devices running Android 9 or lower might not have
support for Wi-Fi MAC randomization. When upgrading such devices to Android
10, the Wi-Fi MAC randomization feature can be disabled
by setting the WIFI_HIDL_FEATURE_DISABLE_AP_MAC_RANDOMIZATION flag to true in
the Wi-Fi vendor HAL make file.
Validation
To validate that the feature is working as intended, run a manual test:
Verify that MAC randomization is enabled on the device by checking that
config_wifi_connected_mac_randomization_supported is set to true in the
device overlay.
Connect to a Wi-Fi network.
Tap the network to go to the Network details page. Verify that MAC
randomization is turned on. Verify that the MAC address displayed is a
randomized MAC, which has the locally generated bit set to 1 and the
multicast bit set to 0.
Turn MAC randomization off. Connect to the same network and verify
that the factory MAC is being used.
Delete the network by tapping Forget on the Network details page.
Connect to the same network and verify that the same randomized MAC
address is being used.
To test MAC randomization on a pre-Android 10 device
(capable of supporting MAC randomization) upgrading to Android
10 or higher:
Have at least one saved network on a device running
Android 9 or lower.
Flash the Android 10 system image.
In the Wi-Fi picker, verify that MAC randomization is turned off for all
saved networks.
Turn MAC randomization on. Connect to the same network and verify
that the randomized MAC is being used.
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Last updated 2025-06-26 UTC.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-06-26 UTC."],[],[],null,["# Implement MAC randomization\n\nStarting in Android 8.0, Android devices use randomized MAC addresses when\nprobing for new networks while not associated with a network. In\nAndroid 9, you can enable a developer option (it's\n**disabled** by default) to cause the device to use a randomized MAC address\nwhen connecting to a Wi-Fi network.\n\nIn Android 10, MAC randomization is enabled by default\nfor client mode, SoftAp, and Wi-Fi Direct.\n\nMAC randomization prevents listeners from using MAC addresses to build a history\nof device activity, thus increasing user privacy.\n\nAdditionally, MAC addresses are randomized as part of\n[Wi-Fi Aware](/docs/core/connect/wifi-aware) and\n[Wi-Fi RTT](/docs/core/connect/wifi-rtt) operations.\n\nFor more information, see\n[MAC Randomization Behavior](/docs/core/connect/wifi-mac-randomization-behavior).\n\nImplementation\n--------------\n\nTo implement MAC randomization on your device:\n\n1. Work with a Wi-Fi chip vendor to implement the following HAL methods:\n\n - `IWifiStaIface#setMacAddress`: Configures the MAC address of the interface. The default implementation brings the interface down, changes the MAC address, and brings the interface back up.\n - `IWifiStaIface#getFactoryMacAddress`: Gets the factory MAC of `wlan0` using an `ioctl` call.\n - `ISupplicantP2pIface#setMacRandomization`: Sets P2P MAC randomization on/off in the supplicant.\n2. Set\n [`config_wifi_connected_mac_randomization_supported`](https://android.googlesource.com/platform/frameworks/base/+/refs/heads/android16-release/core/res/res/values/config.xml)\n to `true` in the Settings `config.xml` (this can be done in a device\n custom overlay).\n\n - This flag is used to control whether client-mode MAC randomization is enabled.\n3. Set\n [`config_wifi_p2p_mac_randomization_supported`](https://android.googlesource.com/platform/frameworks/base/+/refs/heads/android16-release/core/res/res/values/config.xml)\n to `true` in the Settings `config.xml` (this can be done in a device\n custom overlay).\n\n - This flag is used to control whether Wi-Fi direct MAC randomization is enabled.\n4. Test your implementation using the methods described in\n [Validation](#validation).\n\nThe System UI must:\n\n- Have an option to enable or disable randomization for each SSID.\n- Have MAC randomization enabled by default for all newly added networks.\n\nUse the\n[reference implementation](https://cs.android.com/android/platform/superproject/+/android-latest-release:packages/apps/Settings/src/com/android/settings/wifi/details2/WifiPrivacyPreferenceController2.java)\nof Settings UI to implement new prompts.\n\nDevices running Android 9 or lower might not have\nsupport for Wi-Fi MAC randomization. When upgrading such devices to Android\n10, the Wi-Fi MAC randomization feature can be disabled\nby setting the `WIFI_HIDL_FEATURE_DISABLE_AP_MAC_RANDOMIZATION` flag to true in\nthe Wi-Fi vendor HAL make file.\n\nValidation\n----------\n\nTo validate that the feature is working as intended, run a manual test:\n\n1. Verify that MAC randomization is enabled on the device by checking that `config_wifi_connected_mac_randomization_supported` is set to `true` in the device overlay.\n2. Connect to a Wi-Fi network.\n3. Tap the network to go to the Network details page. Verify that MAC randomization is turned on. Verify that the MAC address displayed is a randomized MAC, which has the locally generated bit set to 1 and the multicast bit set to 0.\n4. Turn MAC randomization off. Connect to the same network and verify that the factory MAC is being used.\n5. Delete the network by tapping **Forget** on the Network details page.\n6. Connect to the same network and verify that the **same** randomized MAC\n address is being used.\n\n | **Note:** Randomized MAC addresses are generated per SSID and are persistent.\n\nTo test MAC randomization on a pre-Android 10 device\n(capable of supporting MAC randomization) upgrading to Android\n10 or higher:\n\n1. Have at least one saved network on a device running Android 9 or lower.\n2. Flash the Android 10 system image.\n3. In the Wi-Fi picker, verify that MAC randomization is turned off for all saved networks.\n4. Turn MAC randomization on. Connect to the same network and verify that the randomized MAC is being used.\n\n| **Note:** You may experience up to a three-second delay when connecting to a network due to the driver flushing saved scan results when the interface goes down. If this is the case, check with your silicon partners to resolve the issue."]]
