MAC address lookup
Identify the hardware vendor behind a MAC address from its OUI.
This MAC address lookup identifies the manufacturer of a network device from the first half of its MAC address. The leading three bytes form the OUI, an organizationally unique identifier that the IEEE assigns to each hardware vendor, so matching that prefix reveals who made the network card or chipset. It is useful for inventorying devices on a network, spotting unfamiliar hardware, and troubleshooting connectivity. Paste a MAC address in any common format and the tool normalizes it and returns the associated vendor.
Frequently asked questions
What part of the MAC address identifies the vendor?
The first three octets, called the OUI, are registered to a manufacturer. The remaining octets are assigned by that manufacturer to individual devices.
Why does a vendor not show up?
The address may use a private or randomized prefix, or the OUI may not be in our common-vendor set. Modern phones often randomize MAC addresses for privacy, which deliberately hides the vendor.
Do different formats work?
Yes. Colon, hyphen, and dotted notations are all accepted and normalized before the lookup.
How do I tell a randomized MAC from a real one?
Locally administered addresses have the second-least-significant bit of the first octet set to 1 — in practice the second hex digit is 2, 6, A, or E. Those are typically privacy-randomized and won't map to a real vendor.
What is the difference between an OUI and a full MAC?
The OUI is just the first three bytes that identify the manufacturer; the full six-byte MAC adds three more bytes that the manufacturer assigns to each individual device. Only the OUI is needed for a vendor lookup.
Why might two devices show the same vendor?
They likely share a network chipset or were made by the same manufacturer, who registered one OUI for many products. The vendor reflects the hardware maker, not necessarily the brand on the box.
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