MAC Address Lookup
Enter any MAC address, OUI, or IAB to find the manufacturer, the registered address, and the block it belongs to.
Any format works: colons, dashes, dots, or bare hex.
Searching 58,260 assignments from 34,006 organizations across 118 countries.
Lookups run entirely in your browser. Nothing you type is sent to a server.
Tools
Bulk lookup
Paste a list or drop in a file. Thousands of addresses resolved in your browser, exportable as CSV.
MAC generator
Random addresses with control over separator, case, vendor prefix, and the local and multicast bits.
Free API
JSON, XML, CSV, or pipe-delimited. No key, no sign-up, and the same data the site uses.
Cisco vendorMacs.xml
A current vendor file for Prime Infrastructure and the WLC, so clients stop resolving as Unknown.
Largest registrants
All vendorsHow it works
A MAC address is 48 bits. The first 24, 28, or 36 of them are a prefix the IEEE sold to one organization; the rest are chosen by that organization. A lookup matches the longest registered prefix, which is the only way to get the right answer when a small block sits inside a larger company's range.
The whole registry is published here as static files, so your browser downloads a few kilobytes covering the prefix you asked about and resolves the answer locally. There is no query sent anywhere.
Data comes straight from the IEEE Registration Authority and is re-imported daily. See the statistics for what is in it, or the FAQ for why a lookup sometimes comes back empty.