MAC Address Tools (Format, Vendor Lookup)
Parse and normalise MAC addresses in any common format (aa:bb:cc:dd:ee:ff, aa-bb-cc-dd-ee-ff, aabb.ccdd.eeff, aabbccddeeff). Decode the multicast and locally-administered bits. Look up the OUI (Organisationally Unique Identifier) against the most common vendor prefixes.
How to use the MAC Address Tools (Format, Vendor Lookup)
Paste a MAC address in any format. The tool normalises it to canonical aa:bb:cc:dd:ee:ff form, then breaks it down: OUI (first 3 bytes = manufacturer ID), unicast/multicast bit, globally/locally administered bit, and possible vendor name.
Decoding a MAC address
A MAC address is the 48-bit hardware identifier on a network interface, and it encodes more than a serial number. The first three bytes are the OUI, an Organisationally Unique Identifier assigned to the manufacturer, so they often reveal the vendor. Two bits in the first byte are flags: the multicast bit distinguishes a single device from a group address, and the locally-administered bit marks an address that was set in software rather than burned in at the factory — the signature of a randomised privacy MAC.
Paste an address in any common format and this normalises it, decodes those bits, and looks the OUI up against common vendor prefixes. It works at layer 2 (the hardware address); to inspect the layer-3 IP address on the same interface, use the IP address tools.
Common use cases
- Vendor lookup — identify the likely manufacturer from the OUI.
- Format normalisation — convert any notation to canonical colon form.
- Spotting randomised MACs — detect the locally-administered privacy bit.
- Multicast detection — tell group addresses from unicast ones.
- Network inventory — tidy and classify addresses from a device list.