What a MAC address is and why you need it

A MAC address is a unique identifier assigned to your computer's network card — the hardware that connects you to Wi-Fi or ethernet. It looks like a string of six pairs of numbers and letters, separated by colons or hyphens: for example, 00:1A:2B:3C:4D:5E. Your router uses it to recognize your device on the network.

You need your MAC address when you set up a new Wi-Fi network, register a device with your internet provider, or troubleshoot connection problems. Some networks — particularly in offices, schools, and apartment buildings — only allow devices with registered MAC addresses to connect. If your internet stops working and your provider asks for it, knowing where to find it saves you a support call.

Every device with a network card has one: your laptop, desktop, phone, and printer all have their own. If your computer has both Wi-Fi and ethernet, it has two different MAC addresses.

Key Takeaways

  • Your MAC address is a unique identifier for your computer's network hardware, shown as six pairs of numbers and letters like 00:1A:2B:3C:4D:5E.
  • In Windows, open Command Prompt and type ipconfig /all to find it listed as "Physical Address" next to your network adapter.
  • On a Mac, go to System Settings > Network, select your connection, and click Details to see the MAC address labeled "Wi-Fi Address" or "Ethernet Address".
  • In Linux, open a terminal and type ip link show or ifconfig to see the MAC address next to "link/ether" or "HWaddr".
  • If your computer has both Wi-Fi and ethernet, you will see two different MAC addresses — one for each connection type.

Finding your MAC address in Windows

Open the Start menu and type cmd into the search box. Click Command Prompt to open it. At the prompt, type ipconfig /all and press Enter. A list of network information will appear on your screen.

Look for the section labeled with your network adapter name — usually "Ethernet" if you are plugged in with a cable, or "Wireless LAN adapter Wi-Fi" if you are on Wi-Fi. Below the adapter name, find the line that says Physical Address. The string of characters next to it is your MAC address. Write it down or take a screenshot if you need it later.

If you have both ethernet and Wi-Fi, you will see two separate adapter sections, each with its own Physical Address. The one you need depends on how your computer connects to the network — use the ethernet address if you are plugged in, or the Wi-Fi address if you are wireless.

Finding your MAC address on a Mac

Click the Apple menu in the top-left corner and select System Settings. In the sidebar, click Network. Select the connection you want to check — Wi-Fi if you are wireless, or Ethernet if you are plugged in with a cable.

Click the Details button in the bottom-right corner of the window. A new panel will open. Look for the line labeled Wi-Fi Address (for wireless) or Ethernet Address (for wired). The string of characters next to it is your MAC address.

If you need the address for a connection you are not currently using, go back to the Network list and select that connection instead, then click Details again. Each connection type has its own MAC address.

Finding your MAC address in Linux

Open a terminal window. Type ip link show and press Enter. A list of network devices will appear. Look for the device you want — usually eth0 for ethernet or wlan0 for Wi-Fi. On the line that starts with link/ether, the string of characters when ready after it is your MAC address.

If ip link show does not work on your system, try ifconfig instead. Look for the line labeled HWaddr (hardware address) under your network device. The string next to it is your MAC address.

Both commands show all network devices on your computer. If you have multiple adapters, you will see multiple MAC addresses — one for each device. Identify which one you need by checking which adapter is currently active or which one connects to your network.

What to do once you have your MAC address

Once you have written down or copied your MAC address, you can use it to register your device with your internet provider, add it to a network's approved device list, or provide it to technical support if you are troubleshooting a connection problem. Keep it somewhere you can find it again — a note in your phone, a document on your computer, or a sticky note near your router.

If you are setting up a new network and need to register multiple devices, collect the MAC address from each one before you start. This is faster than looking them up one at a time later. If you ever replace your network card or get a new computer, the MAC address will change — the old one will no longer work on the network.

Frequently Asked Questions

Can I change my MAC address?

Yes, but it is not permanent. You can temporarily change your MAC address using software, which is sometimes called "spoofing." However, the change only lasts until you restart your computer. If you need a permanent change, you would need to replace the network hardware itself, which is not practical for most users.

Why does my computer show two different MAC addresses?

Your computer has one MAC address for each network adapter. If you have both Wi-Fi and ethernet, you have two adapters and two addresses. Some computers also have additional network devices. Use the address that matches the connection type you are actually using.

What if I cannot find the MAC address using these steps?

Make sure you are looking at the correct section of the output — it is straightforward to miss if you are scanning quickly. In Windows, search for "Physical Address" specifically. On a Mac, make sure you clicked Details after selecting your network. In Linux, check that you typed the command correctly and pressed Enter.

Is my MAC address the same as my IP address?

No. Your MAC address identifies your device on your local network, while your IP address identifies it on the internet. They serve different purposes. Your MAC address stays the same, but your IP address can change when you connect to a different network or restart your router.