How to look up a MAC address
- Type or paste an address into MAC address or first 6 digits (OUI). Colons, hyphens, Cisco-style dots and no separators all work, in any case. Short groups such as
3c:22:fb:0:34:56, which macOS prints, work too. - Read the Manufacturer line, then the OUI, registry block, address type and administration rows.
- Copy the address from Same address in other formats if you need another style.
How the lookup works
A MAC address is six bytes. The first three are the OUI (Organizationally Unique Identifier), which the IEEE Registration Authority assigns to one company, and that company numbers the last three bytes. The tool matches your address against a copy of the IEEE registries: about 40,000 MA-L blocks (24-bit), plus the MA-M (28-bit) and MA-S and IAB (36-bit) blocks that let small companies share an OUI. The longest prefix wins. Only the OUI is used to pick a small data file from this site, and the rest of the address stays in your browser.
Two bits in the first byte change what an answer means. The lowest bit is 0 for unicast (one device) and 1 for multicast (a group). The next bit is 0 when the manufacturer set the address and 1 when software did, so a second hex digit of 2, 6, A or E means locally administered.
Worked example
The default address 3C:22:FB:12:34:56 returns Apple, Inc. as the manufacturer. The OUI is 3C:22:FB, the registry block is MA-L, 24-bit block, the address type is Unicast (one device) and the administration is Universally administered (set by the manufacturer). The first byte 3C is 00111100 in binary, so both low bits are 0. The same address is shown as 3C-22-FB-12-34-56, 3C22.FB12.3456 and 3C22FB123456. For binary conversions, try the number base converter.
Limits and edge cases
- The registry names the company that bought the prefix, not the model, owner or location.
- Randomized addresses have no manufacturer.
DA:A1:19:12:34:56shows "No manufacturer (locally administered address)" because its second hex digit is A. - Group addresses are not devices.
FF:FF:FF:FF:FF:FFis broadcast,01:00:5Eis IPv4 multicast and33:33is IPv6 multicast, so the tool labels them instead of guessing a vendor. - IEEE splits a few OUIs, such as
70:B3:D5, among many small companies, so enter all 12 digits for those. Some owners are listed as Private. - Virtual machines use the hypervisor's prefix (
00:50:56is VMware), and software can change any MAC, so a match is a strong hint, not proof.
On the same network? See the IP subnet calculator and port lookup.
Frequently asked questions
What is an OUI in a MAC address?
OUI stands for Organizationally Unique Identifier. It is the first three bytes (six hex digits) of a MAC address, such as 3C:22:FB. IEEE assigns each OUI to one organization, which chooses the last three bytes for every device it makes.
How do I find my MAC address on Windows, Mac, iPhone or Android?
Windows 11: Settings > Network & internet > Wi-Fi (or Ethernet) > Hardware properties > Physical address (MAC). Mac: System Settings > Network > Wi-Fi > Details > Hardware > MAC address. iPhone: Settings > General > About > Wi-Fi Address. Android: Settings > About phone > Wi-Fi MAC address (menu names vary by phone).
Why does my phone show an unknown or random vendor?
Phones and laptops use a private, randomized MAC address for each Wi-Fi network. Those addresses have the locally administered bit set (second hex digit 2, 6, A or E), so no manufacturer is registered. Turn off Private Wi-Fi Address on iPhone, or pick Use device MAC on Android, to see the real hardware address.
Can a MAC address tell me the exact device model?
No. The registry only names the company that bought the prefix. Apple alone owns over 1,500 of them, and software can change a MAC address, so a lookup is a strong hint and not proof.
Sources: IEEE public OUI registry and the IEEE Registration Authority. The snapshot date is shown under every result.