MAC Vendor Data Sources and Coverage
The lookup database is built from public IEEE Registration Authority assignments.
Current snapshot
The database contains 54,387 IEEE assignments across 24, 28, and 36-bit prefixes, representing 30,827 distinct registry organisation names.
The IEEE source files installed on this server are dated 9 October 2026. This is the source-file date, not a claim that every assignment was issued on that date.
Registry files
| IEEE registry | Nominal assignment size | Current handling |
|---|---|---|
| MA-L (OUI) | 24-bit prefix | Stored and matched as 24 bits |
| CID | 24-bit company identifier | Retained for registry reference; not a universally unique MAC address block |
| MA-M | 28-bit prefix | Stored and matched as 28 bits |
| MA-S | 36-bit prefix | Stored and matched as 36 bits |
Source files are downloaded from the IEEE Registration Authority. IEEE remains the authoritative source for an assignment.
Legacy export compatibility
Interactive web and API lookups use longest-prefix matching: 36 bits first, then 28 bits, then 24 bits. The downloadable legacy database retains its established six-character mac column for compatibility with existing remote API nodes and therefore contains 40,550 projected 24-bit records.