MAC Address Lookup API

Free, keyless REST access to every IEEE MAC address registration. Existing v1 and v2 endpoints are unchanged.

Endpoint

Pass a MAC address in any format. Six or more hex digits are required; anything beyond the matched prefix is ignored.

GET https://macaddresslookup.app/api/v2/<mac>
GET https://macaddresslookup.app/api/v2/<mac>/<format>
GET https://macaddresslookup.app/api/<format>/<mac>

Example

curl https://macaddresslookup.app/api/v2/00:1B:C5:09:40:00

[
  {
    "startHex": "001BC5094000",
    "endHex": "001BC5094FFF",
    "startDec": 119269834752,
    "endDec": 119269838847,
    "company": "reelyActive",
    "addressL1": "501-1015 rue William",
    "addressL2": "Montreal  Quebec  H3C 1P4",
    "addressL3": "",
    "country": "US",
    "type": "MA-S"
  }
]

Response formats

Format	Path	Content-Type	Notes
JSON	/api/json/<mac>	application/json	Default. An array with a single result object.
XML	/api/xml/<mac>	application/xml	A flat <result> element.
CSV	/api/csv/<mac>	text/csv	One quoted row, no header.
Pipe	/api/pipe/<mac>	text/plain	One pipe-delimited row.

Status codes

200, a registration was found.
204, the MAC is well formed but has no registration. No body is returned.
400, fewer than six hex digits were supplied.
429, rate limited. See below.

Versions

v2 splits the registrant address into addressL1 through addressL3.v1 returns the address as a single address field. Both remain supported; new integrations should use v2.

Rate limits and caching

Requests are limited per IP address. Every response is cacheable, because the registry changes at most once a day, so please respect the Cache-Control header rather than re-requesting the same prefix.

If you are looking up more than a handful of addresses, the whole registry is published as static JSON shards under /data/oui/; that is what this site's own lookup uses, and it costs you one small cached request per prefix instead of an API call per address. For very large workloads, use the bulk downloads.

Data

58,260 assignments across MA-L, MA-M, MA-S, IAB, and CID, refreshed from the IEEE Registration Authority daily.