MAC Address vs IP Address: What's the Difference?
Your device has two important addresses, and people constantly mix them up. The IP address is like your postal address — it can change when you move. The MAC address is like a serial number etched into the hardware — it identifies the device itself, wherever it goes.
What a MAC address is
A MAC (Media Access Control) address is a 12-character hardware identifier burned into every network interface at the factory, written like A4:83:E7:2B:91:0C. The first half identifies the manufacturer; the second half is unique to the unit. Your phone actually has several — one for Wi-Fi, one for Bluetooth.
The key difference: scope
| MAC address | IP address | |
|---|---|---|
| Identifies | The physical hardware | A location on a network |
| Assigned by | Manufacturer | Router (private) / ISP (public) |
| Changes? | Traditionally never | Regularly |
| Visible to | Your local network only | Every site you visit (public IP) |
| Layer | Layer 2 (link) | Layer 3 (network) |
The crucial row is visibility: your MAC address never travels beyond your local network. Websites cannot see it — they only see your public IP. Anyone claiming a website tracked their MAC address is mistaken.
How they work together
Data on your home network is delivered by MAC address; data across the internet is routed by IP address. When your laptop sends traffic to the router, it uses ARP to discover the router's MAC, wraps the IP packet in a frame addressed to that MAC, and hands it over. At every hop across the internet, the MAC layer is stripped and rewritten — only the IP address survives end-to-end.
MAC randomisation: modern privacy protection
Because MAC addresses were permanent, shops and airports once tracked foot traffic by logging the MACs of passing phones. In response, iOS, Android, Windows and macOS now use MAC randomisation — presenting a different, fake MAC to each Wi-Fi network. It's on by default on modern phones and is why your router might show the same phone as multiple "different" devices.
When you'd actually use a MAC address
- Setting a DHCP reservation so a device always gets the same local IP.
- MAC filtering on a router (weak security — MACs are easily spoofed — but occasionally useful).
- Identifying an unknown device on your network by its manufacturer prefix.
Frequently asked questions
Can a website see my MAC address?
No. MAC addresses only exist on your local network segment and are stripped at the first router. Websites see only your public IP address.
Can a MAC address be changed?
Yes — spoofing a MAC in software is trivial on most systems, and modern phones randomise theirs automatically for privacy.