MAC Vendor (OUI) Lookup

Paste any MAC address and see the vendor that owns the registered OUI block. The lookup walks the most-specific match first: OUI-36 / MA-S (36-bit) → MA-M / OUI-28 (28-bit) → OUI-24 / MA-L (24-bit), then falls back to "unknown" if the prefix isn't in the bundled registry. Accepts every common form: 00:1A:2B:3C:4D:5E, 00-1A-2B-3C-4D-5E, 001A.2B3C.4D5E, 001A2B3C4D5E. Paste one, or a whole column (one per line) and copy the result as TSV. The page also surfaces the IEEE 802 tag bits — U/L (locally-administered, common on phones and VMs) and I/G (multicast, including broadcast). Pure client-side, no upload.

MAC address(es)

The lookup runs entirely in your browser — no address ever leaves your device.

Try one — click any chip to load it

IEEE 802 block sizes

MA-L (OUI-24): 24-bit prefix. The vendor owns 2²⁴ = 16,777,216 addresses.
MA-M (OUI-28): 28-bit prefix. The vendor owns 2²⁰ = 1,048,576 addresses.
MA-S (OUI-36): 36-bit prefix (every other nibble of the first 12). The vendor owns 2¹² = 4,096 addresses.
IAB: Individual Address Block — the IEEE name for MA-S under the old allocation rules. Same 36-bit shape.

IEEE 802 tag bits (first octet)

I/G (Individual/Group): Bit 0 of the first octet. 0 = unicast, 1 = multicast / broadcast.
U/L (Universal/Local): Bit 1 of the first octet. 0 = universally administered (assigned by the vendor's OUI). 1 = locally administered — common on Android/iOS MAC-randomisation probes and on cloud-VM NICs whose hypervisor generated the address.