MAC Address Lookup
Look up the manufacturer behind any MAC address, split it into its OUI and device parts, and see whether it is unicast/multicast and universal/locally administered. Matched against the bundled IEEE registry in your browser.
Registered vendor
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How it works
The first 24 bits of a MAC address (the OUI) are assigned to a manufacturer by the IEEE. The lookup matches that prefix against a bundled copy of the IEEE MA-L registry (39,500+ assignments). The two low bits of the first octet reveal whether the address is unicast or multicast (I/G bit) and whether it is globally unique or locally administered (U/L bit).
Modern phones often use randomized, locally administered Wi-Fi MACs for privacy, these have no registered vendor by design. The whole registry is shipped to your browser, so the lookup runs offline; nothing is ever sent to a server.
What this does
A MAC address lookup finds the manufacturer behind a MAC address and splits it into its OUI and device parts.
How to use it
- Paste a MAC address.
- Read the manufacturer.
- See the OUI and device parts.
- Check unicast/multicast and universal/local flags.
How it works
The OUI is the first 24 bits, assigned by the IEEE to a manufacturer. The lowest bit of the first octet marks unicast (0) or multicast (1). Randomized phone MACs set the local bit and have no registered vendor.
Example
A registered OUI prefix resolves to the company that the IEEE assigned it to.
Sources & methodology
Last updated .
Frequently asked questions
What is an OUI?
The Organizationally Unique Identifier is the first 24 bits (first three octets) of a MAC address. The IEEE assigns each block to a manufacturer, so the prefix identifies who made the network hardware.
Why does my phone show no vendor?
Modern phones use randomized, locally administered MAC addresses for Wi-Fi privacy. These set the U/L bit and are not in the registry, so by design they have no registered manufacturer.
What do unicast and multicast mean here?
The lowest bit of the first octet is the I/G bit: 0 marks a unicast address aimed at a single device, 1 marks a multicast address aimed at a group. The all-ones address FF:FF:FF:FF:FF:FF is the broadcast address.
Is my MAC address sent anywhere?
No. The full IEEE registry is shipped to your browser and the lookup runs entirely locally; nothing is uploaded.
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