About MAC Address Analyzer
A locally administered bit is what phone MAC randomisation sets, which is why a vendor lookup returns nothing for many devices on a network scan. That is the feature working as intended rather than a failed lookup.
Identify the manufacturer of any MAC address by matching its OUI against the full IEEE registry, then decode the rest of the address. The lookup runs in your browser.
Every network interface has a 48-bit MAC address whose first 24 bits — the OUI (Organizationally Unique Identifier) — are assigned by the IEEE to a specific manufacturer. This analyzer looks that OUI up against the full IEEE registry to name the vendor, then decodes the rest of the address: it splits the OUI and NIC portions, reads the individual/group bit to tell you whether the address is unicast or multicast, and reads the universal/local bit to show whether it is universally administered (UAA, burned in) or locally administered (LAA, software-set).
It also normalises the address into every common notation — colon, hyphen, Cisco dot and bare — and derives the Modified EUI-64 interface identifier used in IPv6. The IEEE vendor database is fetched only when this tool is opened, so no other page pays for it.