MAC Address Vendor Lookup
Enter a MAC address to see which manufacturer registered its OUI prefix with the IEEE.
Overview
Every network hardware manufacturer registers one or more OUI (Organizationally Unique Identifier) prefixes with the IEEE — the first three bytes of a MAC address. This tool looks up which vendor registered the OUI of the MAC address you enter, so you can identify what kind of device an unfamiliar MAC address on your network belongs to.
The lookup accepts a MAC address in any common notation — colon-separated, hyphen-separated, Cisco dot-separated, or bare hex digits.
Examples
A Raspberry Pi's OUI
B8:27:EB:00:00:00
Raspberry Pi Foundation
How It Works
- Enter a MAC address in any common format.
- Complete the verification check if shown.
- Click Look Up.
- Review the manufacturer registered for that address's OUI prefix.
Use Cases
Identifying unknown devices on a network
Figure out what kind of device an unfamiliar MAC address in your router's client list or network logs belongs to.
Verifying hardware authenticity
Confirm a device's MAC address matches the vendor it claims to be from.
Tips
- Only the first three bytes (the OUI) determine the vendor — the remaining bytes are unique to the individual device and aren't looked up.
- Randomized/private MAC addresses (common on modern phones and laptops when not connected to a saved network) won't resolve to a real vendor, since they aren't drawn from a registered OUI.
FAQ
From a free, public API that maintains the IEEE's OUI registration database, mapping each registered OUI prefix to the organization that registered it.
Either its OUI isn't in the registry, or it's a randomized/locally-administered address (common for privacy features on phones and laptops) rather than one assigned to a real manufacturer.
This lookup queries an external vendor database on your behalf, so a quick bot check helps keep the tool available and responsive for everyone.