Is there a free MAC address lookup API?

Yes. There is a REST API, it needs no key and no registration, and it is free to use under a single rate limit for everyone: 10 requests per second and 25 K requests every six hours.

What a request looks like

Send the address or the prefix in the path:

GET https://api.maclookup.app/v2/macs/00:1A:2B:3C:4D:5E

The accepted notations are listed in the formats the lookup accepts; a prefix of six hexadecimal digits is enough. The same endpoint answers for a MAC prefix at /v2/macs/001A2B, and the API documentation lists the endpoints for company and vendor searches.

What a response contains

A successful lookup for 00:1A:2B returns the field set below. The values are the ones the live API returned:

{
  "success": true,
  "found": true,
  "macPrefix": "001A2B",
  "company": "Ayecom Technology Co., Ltd.",
  "address": "No. 25, R&D Road 2, Science-Based Industrial Park, Hsinchu 300, TW",
  "country": "TW",
  "blockStart": "001A2B000000",
  "blockEnd": "001A2BFFFFFF",
  "blockSize": 16777215,
  "blockType": "MA-L",
  "updated": "2015-11-17",
  "isRand": false,
  "isPrivate": false
}

blockStart, blockEnd and blockSize describe the block the prefix belongs to, and blockType says which kind of IEEE assignment matched. updated is the date the registration last changed, not the date of the request, and isRand and isPrivate mark the two cases where a result needs reading with care: randomized addresses and private registrations. The API documentation defines every field and the response codes.

Rate limits

All users

10 requests/sec

25 K requests/6h

Every response carries headers showing your current allowance, so a client can read its remaining quota instead of guessing. API key registration is no longer available; legacy key holders keep higher limits (50 requests/sec) until April 2027. The rate limit page states the current numbers and the deprecation notice explains the change.

When not to call the API

Every request costs a round trip. An application that resolves addresses in bulk, or that must work without network access, is better served by downloading the vendor database and looking addresses up locally. The API is the right tool for a single address, for data that must be current, and for cases where keeping a copy of the database is not practical.

Sources and review

Last reviewed: 2026-09-16. Technical claims on this page follow the primary sources below; operating-system interfaces change between releases, so check them against your own device version.