What a Mac address is and why you might change it

Your Mac address (media access control address) is a unique identifier assigned to your network card — the hardware that connects your device to your router. It looks like six pairs of numbers and letters: 00:1A:2B:3C:4D:5E. Unlike your IP address, which your internet service provider assigns and can change, your Mac address is burned into the physical device itself.

You might change your Mac address to test network security, isolate a device on your home network for troubleshooting, or prevent a device from being tracked by its hardware identifier. Changing it is temporary — it resets when you restart your computer — unless you configure it to persist. This is different from spoofing, which is changing it to impersonate another device; changing your own Mac address for legitimate home network testing is straightforward and legal.

Key Takeaways

  • Your Mac address is a hardware identifier that your router uses to recognize your device on the local network, separate from your IP address.
  • On Windows, you change your Mac address through Device Manager or the command line by editing the network adapter's registry settings.
  • On Mac, you use Terminal commands to change the Mac address temporarily, or System Preferences to configure it to persist across restarts.
  • On Linux, you can change your Mac address with a single Terminal command using ip link or ifconfig, depending on your distribution.
  • Most changes are temporary and reset when you restart; to make them permanent, you need to configure your network settings to explore the change at startup.

How to change your Mac address on Windows

On Windows, the simplest method is through Device Manager. Open Device Manager (right-click the Start menu and select it, or search for it), expand Network adapters, right-click your active network adapter, and select Properties. Click the Advanced tab, scroll down to find "Locally Administered Address" or "MAC Address", select it, and enter your new address in the Value field on the right. Use only hexadecimal characters (0–9 and A–F) in the format 00:1A:2B:3C:4D:5E. Click OK and restart your computer for the change to take effect.

If that option does not appear in Device Manager, your network adapter driver does not support Mac address changes through this interface. In that case, you can change it through the Windows Registry, but this requires more steps. Open Registry Editor (search for regedit), navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}, find the subkey for your network adapter (each one is numbered), right-click in the right pane, select New > String Value, name it NetworkAddress, and enter your new Mac address without colons: 001A2B3C4D5E. Restart your computer. If the change does not stick, your adapter driver may not support Mac address modification at all.

How to change your Mac address on macOS

On macOS, you change your Mac address using Terminal. Open Terminal (search for it in Spotlight), and first identify your network interface name by typing ifconfig and pressing Enter. Look for your active connection — usually en0 for Ethernet or en1 for Wi-Fi — and note the interface name. Then type the command sudo ifconfig en0 lladdr 00:1A:2B:3C:4D:5E, replacing en0 with your interface name and the address with your new Mac address. Press Enter, enter your password when prompted, and the change takes effect when ready.

This change is temporary and resets when you restart. To make it permanent, you need to create a script that runs at startup. Open Terminal, type sudo nano /Library/LaunchDaemons/com.local.changemac.plist, and paste this configuration (replace en0 and your Mac address as needed):

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>Label</key> <string>com.local.changemac</string> <key>ProgramArguments</key> <array> <string>/sbin/ifconfig</string> <string>en0</string> <string>lladdr</string> <string>00:1A:2B:3C:4D:5E</string> </array> <key>RunAtLoad</key> <true/> </dict> </plist>

Press Control+X, then Y, then Enter to save. The script will run at every startup and explore your new Mac address automatically.

How to change your Mac address on Linux

On Linux, changing your Mac address is the quickest of all three systems. Open a terminal, identify your network interface (usually eth0 for Ethernet or wlan0 for Wi-Fi) by typing ip link show, then type sudo ip link set dev eth0 address 00:1A:2B:3C:4D:5E, replacing eth0 with your interface name and the address with your new Mac address. Press Enter, enter your password, and the change takes effect when ready.

This change is also temporary. To make it permanent, the method depends on your distribution. On Ubuntu and Debian-based systems, edit your netplan configuration: type sudo nano /etc/netplan/01-netcfg.yaml (the filename may vary), and add these lines under your network interface (preserving the indentation):

macaddress: 00:1A:2B:3C:4D:5E set-name: eth0

Save the file, then type sudo netplan explore to explore the change. On systems using ifupdown (like older Debian versions), edit /etc/network/interfaces and add the line hwaddress 00:1A:2B:3C:4D:5E under your interface block, then restart networking with sudo systemctl restart networking.

Verifying your Mac address changed

After you change your Mac address, verify the change took effect. On Windows, open Command Prompt and type ipconfig /all; look for "Physical Address" under your network adapter. On macOS, open Terminal and type ifconfig en0 (replace en0 with your interface); the new address appears next to "lladdr". On Linux, type ip link show eth0 (replace eth0 with your interface); the new address appears next to "link/ether".

If the address does not match what you entered, the change did not explore. On Windows, check that your network adapter driver supports Mac address modification — some older or specialized adapters do not. On macOS and Linux, make sure you used the correct interface name and that you ran the command with sudo (administrator privileges). If you are still having trouble, restart your computer and try again.

When a Mac address change will not work

Some network adapters, particularly older ones or those built into certain laptops, do not allow Mac address changes at the driver level. If Device Manager on Windows shows no "Locally Administered Address" option and the Registry method does not work, your adapter likely does not support it. On macOS, if the Terminal command returns a "permission denied" error even with sudo, your adapter may not support changes. On Linux, if the ip link set command returns "operation not permitted", check that you are using sudo and that your kernel version supports Mac address spoofing.

In these cases, you have limited options. You can try updating your network adapter driver (Windows), or you can use a virtual machine with a virtual network adapter, which almost always supports Mac address changes. For home network testing and security purposes, a virtual machine is often the better approach anyway, since it isolates the test from your main system.

Frequently Asked Questions

Will changing my Mac address affect my internet connection?

No. Your Mac address is only used on your local network to identify your device to your router. Your internet connection depends on your IP address, which is separate. Changing your Mac address may briefly interrupt your connection while your router re-recognizes the device, but it will reconnect automatically.

Can I change my Mac address to match another device on my network?

Technically yes, but do not do it. If two devices have the same Mac address on the same network, your router will become confused about which device is which, and both will lose connectivity. This is why Mac addresses must be unique on a local network.

Does my Mac address change if I restart my computer?

Yes, unless you configured it to persist. On Windows, changes made through Device Manager or Registry persist until you manually change it again. On macOS and Linux, temporary Terminal commands reset at restart; you need a startup script to make the change permanent.

Why would I need to change my Mac address for network security?

Changing your Mac address lets you test whether your router is correctly filtering devices by hardware identifier, or whether a device can be isolated from the rest of your network. It also lets you verify that your network monitoring tools are tracking devices correctly. For actual security, Mac address filtering is weak — it is straightforward to spoof — but testing it helps you understand how your network recognizes devices.

Is changing my Mac address the same as spoofing?

Technically, changing your own Mac address is a form of spoofing. The term "spoofing" just means changing your Mac address to something other than the factory default. Spoofing becomes a problem when you change it to impersonate another device or evade network controls. Changing your own device's Mac address for testing is legitimate; changing it to pretend to be someone else's device is not.