MAC vendor lookup: which manufacturer owns this address?
How does this check work, and what does the result tell you?
AdminKit looks up the IEEE-registered vendor for a MAC address's OUI prefix (its first three bytes) live via its own Check API, and flags locally-administered or randomized addresses that have no vendor to find, which is useful for identifying an unfamiliar device type on your own network, such as a router or camera.
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How it works and limits
Every MAC address’s first three bytes (the OUI, Organizationally Unique Identifier) are assigned by the IEEE Registration Authority to the manufacturer that requested them, so the prefix alone often identifies the maker of a networked device — useful for spotting an unexpected device type on a network, even without a hostname.
What it checks
- The registered manufacturer name for any MAC address’s OUI prefix, looked up live against AdminKit’s copy of the IEEE’s public OUI registry.
- Whether the address is locally-administered or randomised (identifiable from the second-least-significant bit of the first byte) rather than a real factory-assigned address — in which case there is no vendor to find.
- The matched prefix and which size of IEEE assignment block it came from (MA-L, MA-M or MA-S).
Check manually today
Search the first three bytes of the MAC address (e.g. AC:DE:48) in the
IEEE’s own public OUI listing, or in any of the many free OUI lookup
tools that already clear this question for their own use. Remember that a locally administered or randomised address
(common on modern phones and laptops) will not match any manufacturer.
How it compares
See how AdminKit’s MAC vendor lookup compares to macvendors.com, maclookup.app and Wireshark’s OUI Lookup tool for a sourced look at what each one actually offers.
Frequently asked questions
Is this check live?
Yes — it looks up the address you enter against AdminKit's own copy of the IEEE OUI registry via its Check API (GET /v1/tools/mac-vendor), anonymously and rate-limited per visitor.
Why doesn't this identify my phone?
Android 10+ and recent iOS/desktop OSes randomise the MAC address used per network by default, specifically to prevent this kind of tracking — OUI lookup will work best for fixed infrastructure like routers and IoT devices, not personal phones.
What exactly counts as a match?
An exact match against the IEEE registry's published assignments — a 24-bit OUI/MA-L block, or one of the smaller 28-bit (MA-M) or 36-bit (MA-S) blocks IEEE also issues — never a fuzzy or partial match, and never a guess when the prefix isn't registered.
Is the IEEE OUI registry itself reliable?
It's the authoritative source — IEEE is the registration authority that assigns these prefixes to manufacturers — but it is a lookup against an assignment record, not proof of which specific physical device sent a frame, since a vendor can reuse a prefix across many product lines.