A media access control address, or MAC address, is a unique hardware identifier assigned to a network interface such as a Wi-Fi adapter or Ethernet port. It is a 48-bit number written as 12 hexadecimal digits, for example 00:1A:2B:3C:4D:5E, and devices use it to identify each other on the same local network. You can find yours with a single command or in your device network settings.
Key takeaways
- A MAC address is a 48-bit Layer 2 address, written as six pairs of hexadecimal digits.
- The first three bytes (the OUI) identify the manufacturer, and the last three identify the individual interface.
- MAC addresses work on the local network. IP addresses handle routing between networks.
- Modern phones and PCs can use randomized MAC addresses to reduce tracking.
- MAC filtering adds little security, because MAC addresses can be copied or spoofed.
What is a MAC address?
A MAC address is the address that a network interface uses at the data link layer (Layer 2) of the network model. Every Ethernet and Wi-Fi frame carries a source and a destination MAC address, so switches and access points know which device should receive it. Think of the MAC address as the hardware name tag of a network card, while the IP address is its postal address on the wider network.
What does a MAC address look like?
A MAC address has six bytes written in hexadecimal, usually separated by colons or hyphens. The first three bytes form the Organizationally Unique Identifier (OUI), which the IEEE assigns to a manufacturer. The last three bytes are assigned by that manufacturer to the individual interface.
One bit in the first byte marks a locally administered address. Randomized and virtual MAC addresses usually set this bit, which is why they can look different from the vendor range.
MAC address vs IP address: what is the difference?
A MAC address identifies a network interface on the local network, while an IP address identifies a device on a network and can change. The table summarizes the differences.
| Feature | MAC address | IP address |
|---|---|---|
| Layer | Data link (Layer 2) | Network (Layer 3) |
| Length | 48 bits, 12 hex digits | 32 bits (IPv4) or 128 bits (IPv6) |
| Assigned by | Manufacturer, or generated by the device | Network (DHCP) or administrator |
| Scope | Local network segment | Local and internet-wide routing |
| Changes often? | Rarely, unless randomized or changed | Often, depending on network |
The Address Resolution Protocol (ARP) links the two on IPv4 networks. A device asks who has a given IP address, and the owner replies with its MAC address. Routers use IP addresses to move traffic between networks, as explained in our guide to static vs dynamic routing.
How do you find your MAC address?
You can find your MAC address in network settings or with a command. Use the method for your device:
- Windows: open Command Prompt and run
ipconfig /all, then read Physical Address for your adapter. You can also rungetmac. - macOS: open System Settings, Network, choose the connection and open Details, then Hardware. Or run
ifconfig en0 | grep etherin Terminal. - Linux: run
ip linkand read the link/ether value for the interface. - iPhone and iPad: open Settings, General, About, and read Wi-Fi Address. If Private Wi-Fi Address is on, the address used on a network may differ.
- Android: open Settings, About phone, and look for Wi-Fi MAC address. Menu names vary by maker and version.
- Router or switch: check the label on the device or the connected devices list in the admin page.
What is a MAC address used for?
MAC addresses are used to deliver frames on a local network and to identify devices for management tasks. Common uses include:
- Switches learn which port each MAC address sits behind. Problems such as collisions are covered in our guide to network collisions.
- DHCP servers can reserve the same IP address for a device by its MAC address.
- Network teams use MAC addresses for inventory and troubleshooting, often documented at the patch panel or IDF.
- Wake-on-LAN sends a magic packet that contains the target MAC address.
- Some networks use MAC filtering or MAC-based authentication to allow known devices.
Can a MAC address be changed or spoofed?
Yes. Most operating systems and many network drivers let you set a different MAC address, and attackers can copy the address of an allowed device. That is why MAC filtering is a weak security control on its own. Rogue hotspots can also use this trick, as described in our Wi-Fi Pineapple guide. Wireless detection systems such as WIPS can spot spoofing and unknown devices. For home networks, strong encryption matters more, as covered in our guide to protecting your Wi-Fi from hackers.
What is MAC address randomization?
MAC address randomization makes a device use a changing or per-network MAC address instead of its permanent hardware address. It reduces the ability of shops, hotspots and trackers to follow a device across places. iOS calls it Private Wi-Fi Address, Android has a randomized MAC option for Wi-Fi networks, and Windows offers Random hardware addresses. It can affect networks that rely on MAC filtering, so you may need to turn it off for a trusted home or office network.
Frequently asked questions
Is a MAC address unique?
Hardware MAC addresses are intended to be globally unique because of the manufacturer prefix, but addresses can be changed, randomized or duplicated by mistake. Treat uniqueness as the default, not a guarantee.
Can someone find my location from my MAC address?
A MAC address does not reveal your location by itself, and it stays on the local network. However, hotspots and networks can log it, and a known address can be matched to past visits, which is why randomization exists.
What is the difference between a MAC address and a Wi-Fi address?
On a phone, Wi-Fi Address is just the label for the MAC address of the Wi-Fi adapter. A device with Wi-Fi, Ethernet and Bluetooth has a separate MAC address for each interface.
Does a MAC address change when I change networks?
Not normally. With randomization on, the device can use a different address for each network.
How long is a MAC address?
A MAC address is 48 bits, which is six bytes or 12 hexadecimal digits.
Conclusion
A MAC address is the hardware-level name that lets devices talk on the same local network. Know the format, learn how to find it, and use it for inventory and reservations, but do not rely on MAC filtering for security. Combine strong encryption, current devices and monitoring for a safer network.
