MAC Address Lookup

What is a MAC address?

A Media Access Control address is a 48-bit hardware identifier burned into (or randomly assigned by) every network interface — your Wi-Fi adapter, your Ethernet port, your Bluetooth chip. It's how devices on a local network find each other at Layer 2, before any IP addressing comes into play. Your router uses MAC addresses to deliver packets to the right device on your LAN; outside the LAN, MAC addresses don't travel — only IPs do.

What is an OUI?

The Organisationally Unique Identifier is the first 3 bytes (24 bits) of a MAC address, assigned to a manufacturer by IEEE. The remaining 3 bytes are assigned by the manufacturer to individual devices off their production line. So 00:1A:2B:XX:XX:XX is one OUI block of 16 million possible addresses, and the OUI alone (00:1A:2B) is enough to identify the company that made the hardware.

This tool ships with the full IEEE MA-L registry — roughly 39,000 OUI assignments covering essentially every device vendor that has ever registered. The vendor directory lists the top 2,000 manufacturers by assignment count.

How to find your MAC address

• Windows — open Command Prompt → ipconfig /all → look for "Physical Address" under your active adapter.
• macOS — System Settings → Network → select the active interface → Advanced → Hardware.
• Linux — ip link show or the older ifconfig — the address is shown as link/ether.
• iPhone / iPad — Settings → General → About → Wi-Fi Address.
• Android — Settings → About Phone → Status → Wi-Fi MAC Address (path varies slightly by OEM).
• Router admin pages typically list every connected device's MAC alongside its assigned IP and hostname.

MAC address randomisation

Modern devices — iOS 14+, Android 10+, Windows 10+ — randomise their Wi-Fi MAC address per network (or rotate it periodically) to prevent passive tracking across access points. These randomised addresses have the locally administered bit set in the first byte, so they won't match any manufacturer in the IEEE database. If a lookup tells you "locally administered, no manufacturer match," that's almost always why. It's a privacy feature, not a bug.

The same bit is set for any address an administrator assigns manually to a virtual interface (libvirt, Hyper-V, KVM, etc.) — the lookup tool flags it the same way.

MAC vs IP

MAC addresses work at Layer 2 — the local network only. IPs work at Layer 3 — they're internet-routable. Your router uses the Address Resolution Protocol (ARP) to map between the two on your LAN: when a packet bound for 192.168.1.42 needs to be delivered, the router broadcasts "who has 192.168.1.42?" and the device with that IP answers with its MAC. The packet then gets framed at Layer 2 to that MAC. Outside the LAN, only the IP travels — every router along the path rewrites the Layer 2 framing for the next hop.