Reading the first byte
- Bit 0 (I/G): 0 = unicast (one device), 1 = multicast.
- Bit 1 (U/L): 0 = globally unique, burned in by the manufacturer; 1 = locally administered (random Wi-Fi privacy addresses, virtual machines, Docker).
The first three bytes of a global address are the manufacturer’s OUI. The tool also shows the EUI-64 identifier and the IPv6 link-local address a device builds from the MAC (SLAAC).
Generated MACs are random, unicast and locally administered (second hex digit 2, 6, A or E), so they never clash with real hardware.
Frequently asked questions
Why does my phone show a different MAC on each Wi-Fi?
Modern Android, iOS and Windows use random, locally administered MACs per network for privacy.
Is a MAC address case-sensitive?
No, upper and lower case hex digits mean the same thing.
Can I look up the vendor here?
This tool formats and analyses the address; the OUI (first three bytes) can be checked in the public IEEE registry.