Free MAC address lookup tool. Identify the hardware vendor for any MAC address (or just the OUI prefix, the first three octets). Matched against the live IEEE registry, all 53,000+ MA-L, MA-M and MA-S assignments, updated daily, with longest-prefix matching that resolves MA-S and MA-M blocks to the real vendor instead of a generic registry name. Flags locally-administered / randomised MACs. Useful for network audits, ARP table analysis, device fingerprinting, and identifying unknown devices on your network.
Every network interface, whether it is a laptop's Wi-Fi card, a phone, a router, or a smart bulb, ships with a MAC address: a 48-bit hardware identifier written as six hexadecimal octets, for example AC:DE:48:00:11:22. The first three octets are the OUI (Organizationally Unique Identifier), the block the IEEE assigns to a hardware manufacturer. A MAC address lookup matches that prefix against the IEEE registry to name the vendor. The last three octets are the serial the manufacturer assigns to the individual device and reveal nothing about make, model, owner, or location.
That is the honest limit of any MAC lookup: it identifies who made the network chipset, not the device itself and certainly not a person. It is genuinely useful for network audits, reading an ARP table, spotting an unexpected vendor on your LAN, or fingerprinting a device you cannot physically see.
The IEEE hands out prefixes in three sizes, and getting this wrong is the most common way a lookup returns the wrong vendor. An MA-L assignment gives a company a full 24-bit OUI (about 16 million addresses). Smaller companies get an MA-M (28-bit) or MA-S (36-bit) block, and several companies share the same first three octets under one of these prefixes.
A naive tool that only reads the first three octets will report whichever company happens to own the parent block, which is often wrong for MA-M and MA-S ranges. This tool uses longest-prefix matching across all 53,000+ MA-L, MA-M and MA-S assignments, so a shared prefix resolves to the actual vendor rather than a generic registry name.
If the second-least-significant bit of the first octet is set, the address is locally administered: it was set by software and does not come from any IEEE block, so there is no vendor to find. Modern phones and laptops deliberately do this, they generate a random MAC per network to stop passive tracking across Wi-Fi hotspots. When you look one of these up, the correct answer is "private / randomised", not a guessed manufacturer, and this tool flags them explicitly instead of inventing a vendor.
A MAC address is a 48-bit hardware identifier assigned to a network interface, written as six hexadecimal octets. It identifies a device on a local network segment, separately from its IP address.
The Organizationally Unique Identifier is the first 24 bits (three octets) of a MAC address. The IEEE assigns each OUI to a manufacturer, so looking it up names the vendor of the network hardware.
No. A MAC lookup only identifies the manufacturer of the network chipset. It cannot reveal the model, the owner, or a physical location. The lower half of the address is a per-device serial with no public directory.
When the locally-administered bit in the first octet is set, the address was generated by software rather than assigned from an IEEE block. Phones and laptops randomise their MAC per network for privacy, so the correct result is 'private' rather than a guessed vendor.
The registry is refreshed daily from the official IEEE assignments, so newly registered vendors appear without waiting for a manual database dump.
They are IEEE assignment sizes. MA-L is a full 24-bit OUI (about 16 million addresses). MA-M (28-bit) and MA-S (36-bit) are smaller blocks that several companies share under one prefix, which is why longest-prefix matching is needed to name the real vendor.
Yes. Enter the OUI prefix on its own, for example AC:DE:48, and the tool returns the vendor registered to that block.
Planning to restrict devices by hardware address? See our guide on how to implement MAC address filtering (and why randomised MACs make it weaker than it looks).
Have a whole list to identify (an ARP table or DHCP dump)? Use the Bulk MAC Address Lookup, up to 100 at once with CSV export.
