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 MAC address, short for Media Access Control address. It is a 48-bit number written as six pairs of hexadecimal digits, like 00:1A:2B:3C:4D:5E. The MAC address identifies your specific device on a local network, the same way a street address identifies your house in a neighborhood.

MAC addresses work at a different layer than IP addresses. While an IP address (like 192.168.1.5) routes data across the internet and between networks, a MAC address routes data within a single network — between your device and your router, or between devices on the same WiFi. Your device keeps the same MAC address whether you move to a different WiFi network or city, but your IP address changes.

The first half of a MAC address identifies the manufacturer. If your device has a MAC starting with 00:1A:2B, that prefix belongs to a specific company. The second half is unique to that individual device, assigned by the manufacturer during production.

Key Takeaways

  • A MAC address is a unique identifier for your network device, written as six pairs of numbers and letters like 00:1A:2B:3C:4D:5E.
  • MAC addresses work only on local networks — they route data between your device and your router, not across the internet.
  • The first half of a MAC address identifies the manufacturer; the second half is unique to your individual device.
  • You can find your MAC address in your device's network settings, and some routers let you filter which devices can connect based on MAC address.

How MAC addresses differ from IP addresses

An IP address is like a mailing address that works globally — it tells the internet where to send data so it reaches your device across the world. A MAC address is like a name tag at a local event — it identifies you only within that specific room or network.

When you send data to a website, your device uses both. The IP address gets your request to the right server on the internet. Once the data arrives at your local network, the MAC address directs it to the correct device. Your IP address changes every time you connect to a different network or restart your router. Your MAC address stays the same because it is built into your device's hardware.

A router uses MAC addresses to keep track of which devices are connected to it right now. It uses IP addresses to know where to send data once it leaves the local network and heads toward the internet.

Where to find your MAC address

On Windows, open Command Prompt and type ipconfig /all. Look for "Physical Address" in the results — that is your MAC address.

On Mac, go to System Settings, click Network, select your connection, then click Details. The MAC address appears as "Wi-Fi Address."

On iPhone or iPad, go to Settings, tap General, then About. Scroll down to "Wi-Fi Address."

On Android, go to Settings, tap About Phone, then Status. Look for "Wi-Fi MAC Address."

On Linux, open a terminal and type ip link show or ifconfig. The MAC address is listed as "link/ether."

Why routers and networks use MAC addresses

Routers use MAC addresses to manage which devices connect to them. When you join a WiFi network, your device sends its MAC address to the router. The router remembers it and can assign it the same local IP address each time you reconnect, so your device does not have to renegotiate settings every time.

Some routers let you set up MAC filtering — a whitelist or blacklist of devices allowed or blocked from connecting. This is a basic security tool, though not a strong one because MAC addresses can be spoofed (changed in software). Network administrators in offices and schools sometimes use MAC filtering to control which devices can access the network.

Routers also use MAC addresses to send data to the right physical port. If your router has four Ethernet ports, it uses MAC addresses to know which port each connected device is plugged into.

Can you change your MAC address

Yes, you can change your MAC address in software, a process called MAC spoofing. On Windows, you can change it through network adapter settings. On Mac and Linux, command-line tools let you spoof your MAC address. On phones, most operating systems do not make this easy for everyday users, though it is possible on Android with developer tools.

The change is temporary — it resets when you restart your device or reconnect to the network. To make it permanent, you would have to change it again after each restart.

MAC spoofing has legitimate uses: testing network security, protecting privacy on public WiFi, or bypassing a device blacklist. It also has misuses: connecting to a network you should not access, or impersonating another device. Most networks do not monitor for spoofing, but corporate and institutional networks sometimes do.

MAC addresses and privacy

Your MAC address is visible to any device on your local network, including your router and other computers or phones connected to the same WiFi. It is not sent across the internet, so websites cannot see it.

On public WiFi networks, anyone nearby with a packet sniffer tool can see your MAC address. This is why some people spoof their MAC address on public networks — to avoid being tracked by the same MAC address across multiple visits to the same coffee shop.

Your router logs the MAC addresses of all devices that connect to it. If someone has access to your router's settings, they can see a history of which devices have been on your network.

Frequently Asked Questions

Is a MAC address the same as a serial number?

No. A serial number is a unique identifier for a physical device, printed on it or stored in its firmware. A MAC address is a network identifier that your device uses to communicate on a local network. A device has one serial number but may have multiple MAC addresses if it has multiple network adapters (WiFi, Ethernet, Bluetooth).

Why do some devices have multiple MAC addresses?

Devices with more than one network adapter have a separate MAC address for each. A laptop with both WiFi and Ethernet has two MAC addresses. A phone with WiFi, cellular, and Bluetooth has three. Each adapter needs its own identifier on its respective network.

Can someone track me using my MAC address?

Only on the local network you are connected to. Your MAC address does not travel across the internet, so websites and internet services cannot see it. On public WiFi, nearby devices can see your MAC address, which is why some people spoof it for privacy on untrusted networks.

What happens if two devices have the same MAC address?

Network problems occur. The router cannot tell them apart and may send data to the wrong device. This is rare because manufacturers assign MAC addresses to avoid collisions, but it can happen if someone intentionally spoofs their MAC to match another device on the same network.