What is an OUI in a MAC address?

The OUI (Organizationally Unique Identifier) is the first three bytes of a MAC address — for example 44:19:B6. The IEEE assigns each block to a manufacturer, so the OUI tells you who made the network chip in a device.

How do I find out what manufacturer a device is from its MAC address?

Look up the first three bytes (the OUI) against the IEEE registry. Paste the MAC into this tool and it matches the OUI against a database of common security, AV and network vendors — useful for identifying unknown devices on a camera or building network.

Can a MAC address be spoofed?

Yes — MAC addresses can be changed in software, so vendor lookup identifies the hardware maker, not a guarantee of the device. Modern phones also randomise MACs for privacy. Treat OUI vendor as a strong hint, not proof.

MAC Address Vendor Lookup

Paste a MAC address to identify the manufacturer from its OUI. Built-in database of common CCTV, access control, AV and network brands — runs entirely in your browser, no data sent anywhere.

MAC address

Enter a MAC (any format)

Accepts 44:19:B6:.., 44-19-B6-.., 4419.B612.3456 or 4419B6123456.

Recognises the OUI (first 3 bytes). The bundled list covers common trade brands — for the full IEEE registry, an online lookup has every vendor.

Result

—

manufacturer

OUI (first 3 bytes)—

Device (last 3 bytes)—

Normalised MAC—

Type—

MAC addresses can be spoofed or randomised — treat vendor as a strong hint, not proof.

What do you need next?

LVToolbox Pro

Ready to design the whole network job?

Use the free calculators for quick field checks. Then open LVToolbox Pro to design the network on a floor plan, build your price, and send a professional proposal.

Open LVToolbox Pro →

AMT Systems Ltd. · Toronto & GTA

Prefer a professional to handle it?

AMT Systems can assess, design, quote, and install network and structured cabling across Toronto and the GTA.

Get a Free Quote from AMT Systems →

Using OUI lookup on the job

When you scan a camera network and find an unknown device, its MAC address is the first clue to what it is. The first three bytes — the OUI — are assigned by the IEEE to the company that made the network interface, so 44:19:B6 says Hikvision, 00:40:8C says Axis, 24:A4:3C says Ubiquiti. That's often enough to tell a rogue device from a forgotten camera, or to confirm a switch port is actually connected to the brand of recorder you think it is.

Two caveats keep you honest: MACs can be changed in software, and modern phones deliberately randomise them for privacy (a randomised MAC has a specific bit set — this tool flags it). So OUI vendor identifies the likely hardware maker, not a guaranteed identity.

Frequently asked questions

What is an OUI?

The first three bytes of a MAC, assigned by the IEEE to a manufacturer — e.g. 44:19:B6 = Hikvision.

How do I find a device's maker from its MAC?

Match the OUI against the IEEE registry — which is what this tool does for common security/AV/network brands.

Can MACs be spoofed?

Yes, and phones randomise them. Vendor lookup is a strong hint, not proof of identity.

Unknown devices on your network? Get it audited.

AMT SYSTEMS LTD. audits, segments and secures business networks across Toronto & the GTA — so you know exactly what's connected.

Get a Free Quote