MAC Address Lookup identifies the vendor or organisation registered for a MAC address's OUI, the first three octets, using a short excerpt of the IEEE registry bundled with the page, so the lookup never leaves your browser. It also reads the two flag bits of the first octet: unicast or multicast, and universally or locally administered.
How to read the result
The result shows the registered organisation name for the address's OUI, when found. A locally administered or randomised address (common on modern phones and laptops for privacy) will not match any vendor, which the result notes rather than guessing.
Defender tips
- Expect MAC randomisation on most current phones and laptops when they join Wi-Fi networks; vendor lookup on wireless client lists is increasingly unreliable as an inventory technique for that reason.
- Wired and IoT device inventories are a better fit: those devices are far less likely to randomise their address, so OUI lookup still helps identify unmanaged or unexpected hardware on a network.
FAQ
Why does it say unknown vendor?
Either the OUI is not in the bundled excerpt, which holds common vendors only rather than the full IEEE list, or the address is locally administered or randomised, which by design carries no vendor information.
What is a randomised MAC address?
A privacy feature in modern operating systems that presents a different, non-vendor-linked address per network (or periodically), specifically to prevent tracking a device across networks by its hardware address.
Can this locate a device?
No. It only identifies the manufacturer registered for the address prefix; it has no connection to physical location or IP geolocation.