MAC Address Lookup / Generator

Generate a valid random MAC address or look up the vendor behind one you already have. Generated addresses have the multicast bit cleared so they are always unicast, and lookups match the first three bytes, the OUI, against a curated table of common consumer and virtualisation vendors.

Generate a Random MAC Address

6C:97:D0:6D:AE:1A

Look Up a Vendor from a MAC Address

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Why use MAC Address Lookup?

A MAC address is six bytes that identify a network interface. The first three are assigned by the IEEE to a manufacturer and the last three are chosen by that manufacturer, which is what makes the whole address unique and what makes vendor lookup possible at all. Two bits in the first byte carry meaning beyond identification. The lowest bit distinguishes a unicast address from a multicast one, and the next bit up marks whether the address was assigned by the manufacturer or set locally. Random byte generation would flip both by chance, which is why they are set explicitly here: the multicast bit is cleared so the result always addresses a single interface. Vendor lookup is less reliable than it once was. Phones now randomise their address per network by default to prevent tracking, and those addresses have the locally administered bit set and belong to no manufacturer. A lookup that returns nothing is often telling you something real about the device rather than failing.

Key benefits

Generated addresses are always unicast, since the multicast bit is cleared explicitly
Formatted with colon separators in uppercase, ready to paste into config
Lookup accepts both colon and hyphen separated input
Honest about coverage, saying when a prefix is simply not in the table
Runs in the page with no lookup service involved

Features

Six random bytes with the low bit of the first byte cleared to force unicast
Locally administered bit handled explicitly rather than left to chance
Format validation before any lookup runs
Curated vendor table covering common phone, network, and virtualisation prefixes
One click copy of the generated address

Popular use cases

Creating a placeholder address for a lab, a test fixture, or documentation
Identifying which manufacturer made a device seen on your network
Recognising a virtual machine by its hypervisor prefix in a DHCP table
Filling a MAC field in a config file where the real value does not matter yet

How to use MAC Address Lookup

1
Generate an address
A random MAC is created on load. Press Generate New for another.
2
Copy it if you need it
The generated address is formatted with colons in uppercase, the form most tools expect.
3
Or look one up
Paste a MAC into the lookup field. Colons and hyphens are both accepted as separators.
4
Read the vendor
A match names the manufacturer. No match means the prefix is outside the curated table rather than invalid.

Frequently asked questions

What is an OUI?

The Organizationally Unique Identifier is the first three bytes of a MAC address, assigned by the IEEE to a manufacturer. Those six hex digits identify who made the network interface, while the last three bytes are chosen by the manufacturer to make each device unique.

Why does my address show no vendor?

The table here covers common consumer, networking, and virtualisation prefixes rather than the complete IEEE registry, which runs to tens of thousands of entries. A missing result means the prefix is not in this table, not that the address is invalid. It may also be a randomised address, which modern phones use for privacy.

What makes a generated address valid?

The lowest bit of the first byte is the unicast or multicast flag, and it is cleared here so the address always identifies a single interface. The next bit up marks an address as locally administered, which is set deliberately rather than left to the random value.

Can I use a generated address on a real device?

For lab and testing purposes, yes. Setting a locally administered address avoids any chance of colliding with a manufacturer assigned one. On a production network, changing a MAC can break port security, DHCP reservations, and licence checks tied to the hardware address.

Why do phones show a different MAC on each network?

Modern iOS and Android randomise the address per network by default, so that the same device cannot be tracked across venues by its MAC. Those randomised addresses have the locally administered bit set and will not match any vendor.

Last reviewed: July 2026

Generate a Random MAC Address

Look Up a Vendor from a MAC Address

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