MAC Address Lookup
Your data never leaves your browserFind the manufacturer of any MAC address or OUI from the IEEE registry. Paste arp output to look up a whole network at once.
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How MAC address lookup works
A MAC address is 48 bits, written as 12 hex digits like F0:D1:A9:6B:3E:21. The first half is the OUI (Organizationally Unique Identifier), a prefix the IEEE sells to hardware makers. The second half is a serial number the maker assigns. A MAC address lookup reads the prefix and finds who bought it, so F0:D1:A9comes back as Apple. That's how you put a name to an unknown device in a router's client list, a switch's MAC table or a DHCP log.
This tool searches the IEEE's own MA-L, MA-M, MA-S and IAB registries, about 58,000 blocks in all. It runs the search in your browser by loading only the small slice of the registry for the first three hex digits, so the full MAC addresses you look up never leave your device. Smaller companies buy smaller blocks, and the lookup always picks the most specific one:
| Registry | Identifies the vendor by | Example prefix | Addresses in the block |
|---|---|---|---|
| MA-L | 24-bit prefix | F0:D1:A9 | 16.7 million |
| MA-M | 28-bit prefix | 00:55:DA:1 | 1 million |
| MA-S | 36-bit prefix | 70:B3:D5:00:1 | 4,096 |
Why some MAC addresses have no vendor
The second hex digit gives it away. If it is 2, 6, A or E, as in DA:A1:19:5C:8E:42, the address has its locally administered bit set. Software made it up, and no manufacturer owns it. iPhones, Android phones, Windows and macOS all generate a random address like this for each Wi-Fi network they join, so the same phone looks like a different device on every network. Virtual machines, Docker containers and VPN adapters use locally administered addresses too. The lookup flags these instead of reporting a misleading “not found”.
An odd second digit (1, 3, 5 and so on) marks a multicast address, which a group of devices listens to rather than one. 01:00:5E is IPv4 multicast and 33:33 is IPv6 multicast. The tool also recognizes VRRP and Cisco HSRP virtual router addresses.
How to find a MAC address
| On | Run | Look for |
|---|---|---|
| Windows | getmac /v | or ipconfig /all, listed as Physical Address |
| macOS | ifconfig en0 | grep ether | en0 is usually Wi-Fi |
| Linux | ip link | the address after link/ether |
| Cisco IOS | show mac address-table | every MAC the switch has learned |
| Every device on your LAN | arp -a | paste the whole output above |
Any notation works: colons (00:1a:2b:3c:4d:5e), hyphens as Windows prints them, Cisco's dotted form (001a.2b3c.4d5e), no separator, or just the first 6 digits. The result lists the address in every format, plus the IPv6 link-local address a device builds from it.
Frequently Asked Questions
What is an OUI?
An Organizationally Unique Identifier is the vendor part of a MAC address, normally the first 6 hex digits (24 bits). The IEEE Registration Authority sells OUIs to manufacturers, who then number their network interfaces within that block. Smaller MA-M and MA-S blocks use a 7 or 9 digit prefix instead.
Can a MAC address lookup tell me the exact device?
No. It tells you who made the network interface, not the model or who owns it. A Murata or Espressif result often means a smart home gadget, since those companies make Wi-Fi chips that other brands build in. To narrow it down, match the IP address from your router or arp table and check which ports it has open.
Why does my phone show a different MAC address on each network?
Privacy. Modern phones and laptops use a randomized private address per Wi-Fi network so that shops, airports and hotels cannot track the same device across visits. You can turn it off per network in the Wi-Fi settings, which is useful when a router reserves an IP address by MAC.
How do I look up many MAC addresses at once?
Paste them in, one per line, or paste the raw output of arp -a, ip neigh, a DHCP lease file or a switch MAC table. The tool finds every MAC address in the text, looks each one up, and lists the vendor, country and type in a table you can copy as CSV.
Is the MAC address sent to a server?
No. The vendor registry is split into 1,000 or so small files named after the first three hex digits, such as f0d.tsv, and your browser downloads only the files it needs. Those three digits are all the request reveals, and each file is shared by dozens of vendors. The search runs on your device, so the full address and your list of devices stay in your browser.
Where does the vendor data come from?
From the IEEE Registration Authority, which publishes every assigned MA-L, MA-M, MA-S and IAB block along with the organization and its address. The country shown is the one the vendor registered with the IEEE, not where a particular device was made.
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