How it works
Every MAC address starts with a prefix called the OUI (Organizationally Unique Identifier) that the IEEE assigns to each manufacturer. This tool takes a MAC address or just its prefix and tells you which manufacturer that identifier corresponds to.
It accepts the MAC in the usual formats (with colons, hyphens, or no separators) and queries an IEEE database with a cache to respond quickly. It is useful for identifying unknown devices on a network from their physical address.
Use cases
- Identify the manufacturer of an unknown device that appears on your network.
- Speed up hardware inventories by recognizing the brand from the MAC.
- Detect devices that should not be connected by reviewing their manufacturers.
- Check whether a MAC looks real or spoofed based on its OUI.
Frequently asked questions
What exactly is the OUI?
They are the first 24 bits (the first three octets) of a MAC address. The IEEE assigns them to each manufacturer, so they identify who produced the network interface; the rest of the MAC is assigned by the manufacturer itself to each device.
In what format do I enter the MAC address?
You can paste it with colons (00:1A:2B), with hyphens (00-1A-2B), or without separators. The first three octets are also enough, since the manufacturer is determined by the OUI prefix alone.
Why can't it find the manufacturer of some MACs?
It may be a random or private MAC. Many phones and systems use random addresses for privacy, whose prefix is not assigned to any manufacturer and therefore does not appear.
Does the MAC identify a person?
No. It only indicates the manufacturer of the network interface and is visible within the local network; it does not reveal identity or location, and it can also be changed by software.