Skip to content
TabBench

MAC Address Lookup

Search MAC address hardware vendors from an offline OUI database and normalize MAC notation formats.

Runs in your browser. Nothing you add is uploaded.

What the MAC Address Lookup does

A MAC address (Media Access Control) uniquely identifies every physical network interface card (NIC), Wi-Fi chip, and virtual ethernet controller on a local network. This tool allows network administrators, sysadmins, and security analysts to look up device manufacturers using an offline database of over 150 top IEEE OUI records, normalize inconsistent MAC notations, and inspect individual transmission bits.

How to look up and format MAC addresses

  1. Paste any MAC address formatted with colons, hyphens, dots, or as a raw 12-character hex string.
  2. View the identified manufacturer, OUI prefix, and device vendor details instantly.
  3. Check the transmission mode (Unicast vs Multicast) and administration type (Burned-in vs Locally Administered).
  4. Copy normalized notation formatted specifically for Linux (colon), Windows (hyphen), or Cisco switches (quad-dot).
  5. Click Random MAC to generate valid synthetic MAC addresses for network lab simulations.

The MAC Address Lookup runs entirely in your browser — nothing you enter is uploaded, stored, or logged.

When to use it

DHCP and Network Inventory Management

Quickly identify rogue devices on your corporate Wi-Fi or home router by matching unknown MAC addresses against known hardware manufacturers.

Switch Port Security & Static Leases

Format MAC addresses to match the exact syntax required by Cisco IOS (0011.2233.4455) or Linux dnsmasq configurations without manual string manipulation.

Detecting Randomized Private Wi-Fi MACs

Inspect the U/L bit to determine whether a smartphone is connecting with its real factory hardware address or using randomized private addresses (iOS/Android privacy feature).

Good to know

  • The first 6 hexadecimal digits represent the IEEE Organizationally Unique Identifier (OUI).
  • Locally Administered Addresses (LAAs) have their second hex digit set to 2, 6, A, or E.
  • Multicast addresses always have an odd number as their first octet (the lowest bit is 1).

Frequently asked questions

What is an OUI in a MAC address?

An Organizationally Unique Identifier (OUI) is the first 24 bits (3 octets) of a MAC address assigned by the IEEE to hardware manufacturers to uniquely identify their devices.

How do I know if a MAC address is randomized or virtual?

Look at the second hexadecimal digit of the first octet. If it is 2, 6, A, or E (such as x2, x6, xA, xE), the U/L bit is set to 1, indicating a Locally Administered MAC address commonly used in private Wi-Fi MAC randomization or virtual machines.

Can two devices share the same MAC address?

Globally burned-in MAC addresses from certified vendors should never collide. However, virtual machines and software drivers can spoof or override MAC addresses, creating duplicate MAC conflicts on a local layer-2 collision domain.

Does MAC address lookup work without internet?

Yes. TabBench bundles a comprehensive offline dictionary of common hardware vendors directly in JavaScript, so lookups execute instantly offline.

Related tools