MAC Vendor Lookup
Find registered MAC prefixes using a dated IEEE snapshot
Downloads the IEEE MA-L / MA-M / MA-S snapshot from this site; longest matching prefix wins (36, 28, then 24 bits). No live registry or device identity lookup. Local/group/all-zero addresses are not attributed; your input is not sent in the request.
Snapshot retrieved: 2026-09-30 Β· 54082 assignments. Sources: MA-LMA-MMA-S
Run the tool or try an example to see results.
About this tool
Look up a globally administered unicast EUI-48 address in the bundled IEEE Registration Authority snapshot, retrieved on 2026-09-30 from the public MA-L, MA-M and MA-S CSV files. The browser downloads the database from this site, then matches 36-bit, 28-bit and 24-bit prefixes in that order. The matched prefix, assignment class, registered organization and published address appear in the report. Multiple source rows for the same prefix are preserved and labelled; the tool does not invent a single winner. Local, group and all-zero values are identified without attributing them to a vendor. A registered organization can differ from a finished device manufacturer or current owner. Missing matches may reflect a newer assignment or an unsupported registry class; they do not prove that the MAC is invalid. Paste up to 1,000 lines / 1 MiB. Inputs are not included in the database request, and no third-party per-address service is called.
Failure Clinic (Common Pitfalls)
A familiar vendor name can be an unsupported identity inference
Cause: Registry assignments identify registered organizations. Virtual interfaces, copied addresses and component suppliers break a direct link to a finished device.
Fix: Treat the result as an inventory clue. Preserve the prefix, assignment class, snapshot date and all duplicate rows when investigating a mismatch.
Scenario Recipes
Distinguish an allocation record from device identity
Goal: Find the most specific supported registered prefix and retain source ambiguity.
- Paste complete EUI-48 addresses, one per line, and run the lookup.
- Read the matched MA-L, MA-M or MA-S class and prefix length, then check whether multiple registry rows are present.
- Use the displayed source date and official CSV links when a newer assignment is suspected. Compare device identity with a separate asset record.
Result: A local JSON report of prefix registrants and non-attributable or unmatched addresses.
Production Snippets
Specificity and historical ambiguity
text
36-bit MA-S match β checked before 28-bit MA-M and 24-bit MA-L
02:42:AC:11:00:02 β local; no registrant attribution
08:00:30:00:00:01 β multiple source rows in the 2026-09-30 snapshot
A prefix registrant is not a device model or owner.Frequently Asked Questions
Why use more than the first three bytes?
MA-L uses a 24-bit prefix, MA-M uses 28 bits and MA-S uses 36 bits. The most specific matching allocation is checked first so a smaller assignment is not hidden by its broader prefix.
Does a match identify the actual device manufacturer?
No. The result names the prefix registrant in the downloaded snapshot. It does not establish the device model, current owner, network location or whether the observed address was copied or randomized.
Why are some prefixes shown with several organizations?
The official source can contain multiple rows for the same assignment. Those rows are retained in the JSON report and labelled as multiple registry rows, without choosing one organization by input order.
How current is this database?
The interface shows the retrieval date and links to all three official source CSVs. It is a versioned snapshot, not a live query; later registrations and changes require a future snapshot update.
Why skip locally administered addresses?
When U/L=1, the bytes do not establish a globally allocated device prefix. Looking up an incidental prefix match would imply an ownership relationship that the address does not prove.
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