A MAC address is a unique identifier assigned to every device that connects to a network

Every network device — your laptop, phone, printer, smart TV — has a Media Access Control (MAC) address, a 48-bit number that identifies it on a local network. It looks like this: 00:1A:2B:3C:4D:5E. The MAC address is different from your IP address. Your IP address routes data across the internet; your MAC address routes data within your home network or office network. Think of it this way: the IP address gets a package to your building, and the MAC address gets it to your specific apartment.

MAC addresses are burned into network hardware during manufacturing, though most devices let you change how they appear on a network. They work at Layer 2 of network communication — the data link layer — which means they only matter on networks you're physically connected to or wirelessly joined to. Once data leaves your local network and heads to the internet, routers strip away the MAC address and replace it with routing information based on IP addresses.

Key Takeaways

  • A MAC address is a unique identifier for any device on a local network, separate from the IP address that routes data on the internet.
  • MAC addresses are used by routers and switches to deliver data within a home or office network, not across the internet.
  • You can find your device's MAC address in network settings on Windows, Mac, or Linux, or in your router's connected devices list.
  • MAC filtering lets you control which devices can join your network, and MAC spoofing lets you change how your device appears to a network.
  • Your MAC address is visible to other devices on your local network and to your router, but not to websites you visit.

How MAC addresses work on your network

When you connect to a Wi-Fi network or plug in an Ethernet cable, your device broadcasts its MAC address to the router. The router keeps a table of all connected devices and their MAC addresses. When another device on the network wants to send data to you, the router looks up your MAC address and forwards the data to the correct physical port or wireless channel.

This process happens automatically and invisibly. If you print a document from your laptop to a printer on the same network, your laptop sends the print job to the router with the printer's MAC address attached. The router sees that address, finds the printer, and delivers the job. Without MAC addresses, the router would have no way to know which physical device you meant.

MAC addresses only work on networks you're directly connected to. Once data leaves your local network and heads to the internet, your router replaces the MAC address with routing information based on IP addresses. Websites you visit never see your MAC address — they see only your public IP address, which your internet service provider assigns to your router.

Where to find your device's MAC address

On Windows 10 or 11: Open Settings, go to Network & Internet, then Status. Scroll down and click "View your network properties." Look for "Physical Address" — that's your MAC address. Alternatively, open Command Prompt and type ipconfig /all, then find the line labeled "Physical Address."

On Mac: Open System Settings, click Network, select your connection (Wi-Fi or Ethernet), then click Details. The MAC address appears as "Wi-Fi Address" or "Ethernet Address" depending on your connection type.

On Linux: Open a terminal and type ip link show or ifconfig. The MAC address appears next to "link/ether" or "HWaddr."

On your router: Log into your router's admin panel (usually 192.168.1.1 or 192.168.0.1 in your browser) and look for a section called "Connected Devices," "DHCP Clients," or "Device List." Every device currently on your network will be listed with its MAC address.

MAC filtering and network security

Some routers let you set up MAC filtering, which means you create a list of MAC addresses allowed to join your network. Only devices on that list can connect, even if someone knows your Wi-Fi password. This adds a second layer of security beyond password protection.

To set up MAC filtering, log into your router, find the wireless security or access control settings, and enter the MAC addresses of devices you want to allow. The exact steps vary by router model, but most have this option in the advanced settings. The downside is that you have to manually add every new device, and if you forget a device's MAC address, you'll have to look it up before it can connect.

MAC filtering is useful in small networks where you control all the devices — a home office, a small business, or a household with a fixed set of gadgets. It's less practical for networks where guests frequently connect or where you add new devices often.

MAC spoofing and why it exists

MAC spoofing means changing the MAC address your device reports to the network. Most operating systems let you do this through network settings or command-line tools. Your device still has the same physical MAC address burned into the hardware, but it tells the network a different one.

Legitimate reasons to spoof a MAC address include bypassing MAC filtering on a network you own (if you've forgotten the original address), testing network security, or avoiding tracking on public Wi-Fi. Some people also spoof MAC addresses for privacy — if a coffee shop or hotel tracks devices by MAC address, spoofing makes you appear as a different device each time.

Spoofing is also used maliciously: someone might spoof a trusted device's MAC address to bypass MAC filtering, or spoof a router's MAC address to perform certain network attacks. This is why MAC filtering alone is not a complete security solution — it works best combined with a strong Wi-Fi password and other security measures.

MAC addresses versus IP addresses

The two are often confused because they both identify devices on networks, but they work at different layers and serve different purposes. Your MAC address is a hardware identifier that works only on your local network. Your IP address is a logical address assigned by your network and used to route data across the internet.

Think of it in postal terms: your MAC address is like your apartment number (it only matters within your building), and your IP address is like your full mailing address (it works anywhere in the world). When you visit a website, your IP address tells the server where to send the response. The server never knows your MAC address because it's not included in internet traffic.

On your local network, both work together. Your device uses its IP address to communicate with other devices, but the router uses MAC addresses to figure out which physical device to send the data to. If you change your IP address (by renewing your DHCP lease or setting a static IP), your MAC address stays the same. If you spoof your MAC address, your IP address is unaffected.

What other devices can see about your MAC address

Any device on your local network can see your MAC address if it's looking for it. Your router definitely knows it. Other computers, phones, and smart devices on the same Wi-Fi network can discover it if they run network scanning tools. This is why MAC addresses are not a privacy tool — they're visible to anyone with access to your network.

Websites and internet services cannot see your MAC address. When you browse the web, your MAC address stays on your local network and is never sent to the internet. The server you're connecting to sees only your public IP address (assigned by your internet service provider) and any information you voluntarily provide.

On public Wi-Fi networks, other users on that network could theoretically scan for MAC addresses, but most people don't have the tools or knowledge to do so. The bigger privacy concern on public Wi-Fi is unencrypted traffic and malicious hotspots, not MAC address visibility.

Frequently Asked Questions

Can someone track me using my MAC address?

Only on networks you're connected to. Your MAC address is visible to your router and other devices on the same Wi-Fi network, but it doesn't travel across the internet. Websites and internet services cannot see it. On public Wi-Fi, someone with network scanning tools could identify your device by MAC address, but this is uncommon. If privacy is a concern, use a VPN on public networks.

What happens if two devices have the same MAC address?

Network communication breaks down. The router won't know which device to send data to, and both devices will experience connection problems. This is rare because manufacturers assign MAC addresses in blocks to avoid collisions. If it happens, it's usually because someone intentionally spoofed a MAC address. Change the spoofed address or restart the device to fix it.

Do I need to know my MAC address for anything?

You might need it to set up MAC filtering on your router, to register a device on a network that requires it, or to troubleshoot connection problems. Most of the time, your device handles MAC addresses automatically and you never need to think about it. If your internet service provider asks for your MAC address, they usually mean your router's MAC address, not your computer's.

Can I change my MAC address permanently?

No. The MAC address is burned into your network hardware during manufacturing and cannot be permanently changed. You can spoof it — make your device report a different address to the network — but the original address is still there. If you restart your device or disconnect from the network, the spoofed address usually reverts to the original.

Is my MAC address the same on Wi-Fi and Ethernet?

No. Each network interface has its own MAC address. Your laptop's Wi-Fi adapter has one MAC address, and its Ethernet port has a different one. Your phone's Wi-Fi MAC address is different from its cellular MAC address. When you connect using one interface, only that interface's MAC address is visible to the network.