What MAC address formats are supported?

The tool accepts colon-separated (AA:BB:CC:DD:EE:FF), hyphen-separated (AA-BB-CC-DD-EE-FF), Cisco dot notation (AABB.CCDD.EEFF), and raw 12-character hex strings.

The OUI (Organizationally Unique Identifier) is the first three octets of a MAC address. It identifies the manufacturer of the network interface.

What does "locally administered" mean?

If the second-least-significant bit of the first octet is set, the address was locally assigned rather than globally registered with the IEEE.

MAC Address Validator - Validate & Decode MAC Addresses

MAC Address Validator

A MAC (Media Access Control) address is a 48-bit hardware identifier assigned to network interfaces. This tool validates any MAC address format, identifies special address types, and shows the OUI prefix used to identify the manufacturer.

Accepted formats

Colon: AA:BB:CC:DD:EE:FF (most common on Linux/macOS)
Hyphen: AA-BB-CC-DD-EE-FF (common on Windows)
Cisco dot: AABB.CCDD.EEFF
Raw hex: AABBCCDDEEFF

Address types

Broadcast (FF:FF:FF:FF:FF:FF) is delivered to all devices on a network segment. Multicast addresses have the LSB of the first octet set to 1. Locally administered addresses (LAA) have the second LSB of the first octet set to 1 and were manually assigned rather than burned into hardware.

OUI examples

The first three octets (24 bits) of a MAC address form the Organizationally Unique Identifier (OUI), assigned by the IEEE to each manufacturer. Examples of well-known OUI prefixes:

OUI prefix	Manufacturer
`00:03:93`	Apple
`AC:DE:48`	Apple (newer)
`00:00:0C`	Cisco
`DC:A6:32`	Raspberry Pi Foundation
`00:50:56`	VMware (virtual NIC)
`08:00:27`	VirtualBox (virtual NIC)
`00:1A:11`	Google

Privacy and MAC randomization

Modern operating systems randomize MAC addresses when scanning for Wi-Fi networks to prevent tracking. iOS 14+, Android 10+, and Windows 10/11 all enable MAC randomization by default for Wi-Fi probe requests. When connected to a saved network, a randomized (but stable) address is typically used per-network.

A randomized address has the locally administered bit set (second LSB of the first octet = 1), so it will not match any OUI in the IEEE registry. If this tool flags a MAC as "locally administered," it is likely a privacy-randomized address rather than a manually configured one.

Common use cases

Router MAC filtering: some router admin panels allow only listed MAC addresses to connect. Validating the address format before entry prevents typo-related lockouts.
DHCP reservations: assigning a fixed IP address to a specific device by its MAC - useful for servers, printers, and smart home devices.
Network monitoring and asset inventory: identifying devices on a network by their OUI helps distinguish authorized hardware from unknown devices.