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Who owns this MAC address?

We get this question by email most weeks. The honest answer is shorter than people hope.

A MAC address lookup tells you which company made the device's network interface. That is all it can tell you. It cannot tell you who bought the device, where it is, or what its IP address is, and nobody else can look those things up from a MAC address either. Here is why, and what you can usefully do instead.

What a lookup actually returns

The IEEE sells blocks of addresses to companies that make network hardware. Each company stamps addresses from its block into the chips it makes. The IEEE publishes the list of blocks and who registered them, and that list is what we search. So a lookup returns the organization that registered the block, usually the maker of the device or of the Wi-Fi chip inside it.

That is why you sometimes get a name you have never heard of. A laptop may show up as AzureWave or Intel, because they made the wireless card. A smart bulb may show up as Espressif or Tuya, because they made the module inside. Contract manufacturers like Hon Hai build devices for many brands, so their name tells you very little.

Note: The registry records who bought the block, in lots of thousands or millions of addresses. It does not record who bought any individual device. Nobody keeps that list.

What it cannot tell you

  • The owner. No name, email, phone number or account is attached to a MAC address anywhere.
  • The location. A MAC address contains no geographic information at all.
  • The IP address. The two are unrelated. See our guide on MAC addresses and IP addresses.
  • The serial number or model. The vendor is the most specific thing you get.
  • Whether the device is online, or where it has been.

We cannot look these up, the IEEE cannot, your Internet provider cannot, and no paid service can either. A site that claims to find a person or a street address from a MAC address is guessing.

Note: One narrow exception. The wireless addresses of Wi-Fi routers and access points are collected by the positioning services phones use to find their location indoors, so a router's Wi-Fi address can sometimes be matched to a rough area. Phones, laptops and other client devices are not in those databases.

Why a MAC address never leaves your network

A MAC address is only used to deliver data across one local network, such as your home Wi-Fi. When your traffic reaches your router and heads out to the internet, the router replaces your device's MAC address with its own, and the next router does the same, and so on. A website you visit never sees your MAC address. Neither does anyone else on the internet.

So "someone online has my MAC address" is rarely true, and if it were, there is almost nothing they could do with it from outside your network. The things a MAC address can be abused for, like getting past a router's allow-list, all require being within Wi-Fi range.

What you can do with one

  • Identify a device on your own network. Combined with your router's device list, the vendor is usually enough to work out what something is. Our step-by-step guide walks through it.
  • Check a device is what it claims to be. A "genuine" network card whose address belongs to a company you have never heard of is worth a second look.
  • Set up your router. DHCP reservations, allow-lists and parental controls are all keyed on MAC addresses.
  • Spot randomized addresses. If the lookup says locally administered, the device is making up an address, which modern phones do by default. Our guide to those results explains it.

If you found a device you do not recognise

Start with the unknown devices guide . Most turn out to be something in the house. If you are sure it is not, change your Wi-Fi password, which disconnects everything, and reconnect your own devices. There is no need to find out who the stranger was first.