MAC Address Vendor Lookup
Find the manufacturer behind a MAC from its OUI, and flag randomized MACs.
This MAC address vendor lookup turns a MAC into the manufacturer that built it. The first three bytes are the OUI, a block the IEEE assigns to one maker, and the tool matches that against the major vendors: networking gear, computers, phones, the big IoT and camera brands. Paste a full address in any format (colons, dashes, Cisco dotted) or just the OUI. It also reads the first byte's flags, so it tells you straight away when an address is multicast, or locally administered, which is the giveaway of a randomized privacy MAC that no vendor can be read from. Everything runs in your browser, so pasting a real device MAC is fine; nothing is sent anywhere.
100% in your browser. Nothing you type ever leaves this page.
- Normalized
- 10:00:20:AA:BB:CC
- OUI (no separators)
- 100020
- First byte
- 0x10 (00010000)
- Cast
- Unicast
- Administration
- Globally unique (OUI)
- Address type
- Real hardware MAC
What the OUI actually tells you
A MAC address is six bytes, and it splits cleanly in half. The first three bytes are the OUI, a block the IEEE hands to a single manufacturer. The last three are chosen by that maker for the individual network card. So this lookup can tell you who built the chip, and nothing more: not the model, not the owner, not where it has been. Paste a full MAC or just the first three bytes; either way only the OUI is read.
Why half your devices say "locally administered"
Open a DHCP lease table on a busy network and a chunk of it looks like garbage MACs with no vendor. That is not a bug, it is privacy working as designed. Phones randomize their MAC per network now, and a randomized address sets the locally-administered bit in its first byte. This tool catches that bit and says so plainly, because chasing a "manufacturer" for a randomized MAC is a waste of an afternoon. The same bit shows up on virtual machines and any address someone set by hand.
Why it does not ship every OUI
The full IEEE registry is tens of thousands of entries, most of them obscure. This tool carries the manufacturers you actually run into: networking gear, laptops and phones, the big IoT and camera brands. It keeps the whole thing small enough to run instantly in your browser. If an OUI is genuinely assigned but not in here, you get an honest "not found" rather than a confident guess, which I think is the right trade for a quick lookup. Need the maker's place in the wider plan? A MAC pairs naturally with our subnet calculator when you are mapping out what is really on a segment.
Frequently asked questions
How does a MAC address reveal the manufacturer?
The first three bytes of a MAC are the OUI (Organizationally Unique Identifier), a block the IEEE assigns to one manufacturer. This tool looks that OUI up in the IEEE registry. The last three bytes are picked by the maker for the individual device and tell you nothing about the vendor.
Why does my phone show as "locally administered" with no vendor?
Modern phones randomize their MAC for privacy: iOS and Android invent a fresh MAC per network instead of using the real one. A randomized MAC has the locally-administered bit set in its first byte, which this tool flags. Its OUI is not a real vendor block, so no manufacturer can be read from it.
Does this carry every OUI in existence?
No, on purpose. It ships the major manufacturers (networking gear, computers, phones, IoT and security devices), not the full IEEE list of tens of thousands. That keeps it small and fast and still covers the kit you actually meet on a network. An OUI that is not in the set shows as not found, never guessed.
What are the U/L and I/G bits?
They are the two lowest bits of the first byte. The I/G bit marks the address as unicast (0) or multicast/broadcast (1). The U/L bit marks it as globally unique from an OUI (0) or locally administered (1), which covers randomized MACs, virtual machines and hand-set addresses.
Does the lookup run in my browser?
Yes. The vendor database is bundled into the page and the match happens locally in JavaScript. Nothing about the MAC you paste leaves your device, which matters because a MAC can identify one specific piece of hardware.