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.
Look up an OUI — the first three bytes of a MAC address — against the IEEE registry to find the organisation it was assigned to. It runs entirely 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.