MAC Address Lookup
Identify the device vendor from a MAC address prefix (OUI).
MAC Address Lookup identifies the manufacturer of a network device from the first part of its MAC address. It is handy for figuring out what a device on your LAN actually is — a router, laptop, phone or IoT gadget — or for checking which vendor an unknown device that just joined your network comes from.
The first 6 hex digits of a MAC address are called the OUI (Organizationally Unique Identifier), assigned to manufacturers by the IEEE. This tool extracts just the OUI from your input, queries a public vendor database, and shows the matching manufacturer name. Any separator works — colons (:), hyphens (-) or dots (.). To check whether a device's IP falls in a private range, pair this with the Private IP Checker.
The free external API is limited to about one request per second. Results are cached per OUI for 24 hours.
MAC address and OUI structure
A MAC address is 48 bits (12 hex digits) and is unique per network interface. It typically splits into two parts:
- First 24 bits (6 digits) — OUI: the identifier the IEEE assigns to a vendor. This is the part that reveals the manufacturer.
- Last 24 bits (6 digits) — NIC: a serial value the vendor assigns to each device. It is not used for vendor lookup.
For example, in 00:1A:2B:3C:4D:5E the OUI is 00:1A:2B, and that value identifies the vendor. The forms 00:1A:2B:3C:4D:5E, 00-1A-2B-3C-4D-5E and001A.2B3C.4D5E all refer to the same address.
Things to know about lookups
- External API rate limit: vendor data comes from a free public API limited to roughly one request per second. Pause briefly between repeated lookups.
- Local/random MAC: when a specific bit (locally administered) in the second hex digit is set, the MAC is not a real vendor OUI. Modern phones use such randomized MACs for Wi-Fi privacy.
- Not registered: if the OUI is not in the database, it shows as unregistered. It may be a new allocation or a private range.