MAC Address Vendor Lookup

What This MAC Address Lookup Does

A MAC address is a hardware identifier used by network interfaces on local networks. The first six hexadecimal characters usually form the OUI, or Organisationally Unique Identifier, which can identify the registered vendor or manufacturer for that prefix.

This tool normalises common MAC address formats, extracts the OUI prefix, and checks it against the local vendor database. It is useful when reviewing switch tables, ARP output, DHCP logs, Wi-Fi clients, network inventories, or security alerts.

Randomised and Locally Administered MAC Addresses

Some devices use private, randomised, or locally administered MAC addresses. These are common on phones, laptops, virtual machines, and privacy-focused Wi-Fi clients. When a MAC address is locally administered, the original hardware vendor may not be visible from the address alone.

You can detect a locally administered MAC address by checking the second-least-significant bit of the first octet. In practice, look at the second hexadecimal character of the MAC address after removing separators. If it is 2, 6, A, or E, the address is locally administered. For example, 02:00:00:12:34:56, 06-1A-2B-3C-4D-5E, 0A1B.2C3D.4E5F, and 0E0000123456 are all locally administered.

Randomised Wi-Fi addresses usually use this locally administered bit so they do not expose the device manufacturer's registered OUI. If a lookup reports an address as auto-generated, private, or vendor not found, check this bit before assuming the vendor database is missing an entry.

Frequently Asked Questions

What is a MAC address?

A MAC address is a unique hardware identifier assigned to a network interface. It is used for communication on local networks and can help identify a device manufacturer.

What is an OUI?

An OUI (Organisationally Unique Identifier) is the first 24 bits of a MAC address. It identifies the organisation or manufacturer that registered that prefix.

Is macvendors.co.uk free to use?

Yes. The single MAC lookup tool is free to use. Bulk lookup and API access are also available for larger workflows and integrations.