MAC address formatter
This MAC address formatter rewrites 48-bit hardware addresses in the style your switch, router or spreadsheet expects. It also tells you whether each address is unicast or multicast and whether the maker assigned it or it was set locally.
- Runs in your browser
- Free, no account needed
- Copy or download the result
Result
Example
00-1A-2B-3C-4D-5E 001a.2b3c.4d5f 02:42:ac:11:00:02 ff:ff:ff:ff:ff:ff
Formatted Delivery Administration OUI Input 00:1a:2b:3c:4d:5e unicast universal 00:1a:2b 00-1A-2B-3C-4D-5E 00:1a:2b:3c:4d:5f unicast universal 00:1a:2b 001a.2b3c.4d5f 02:42:ac:11:00:02 unicast local 02:42:ac 02:42:ac:11:00:02 ff:ff:ff:ff:ff:ff broadcast local ff:ff:ff ff:ff:ff:ff:ff:ff Delivery: the lowest bit of the first byte (I/G). 0 = unicast to one device, 1 = multicast to a group. All ones is broadcast. Administration: the second lowest bit (U/L). 0 = universal, assigned by the maker under its OUI. 1 = locally administered, such as randomized private Wi-Fi addresses and virtual machines. The OUI is the first three bytes. For locally administered addresses it does not identify a maker.
How to use the mac address formatter
- Paste one address per line into the One MAC address per line box. Colons, hyphens, Cisco dots or no separators all work.
- Pick a Format and a Letter case.
- Press Run.
- Use Copy result or Download to take the formatted list.
How it works
Each address must have exactly 12 hex digits in one consistent style; mixed separators are rejected.
The lowest bit of the first byte shows unicast (0) or multicast (1), and an address of all ones is the broadcast address.
The second lowest bit shows whether the address is universal, assigned under the maker's OUI, or locally administered, which is common for random private Wi-Fi addresses and virtual machines.
The tool does not look up vendor names, and 64-bit EUI-64 identifiers are not supported.
Everything runs in your browser. Your input is not uploaded or stored.
Questions and answers
What is a locally administered MAC address?
It is an address with the second lowest bit of the first byte set to 1. Software assigns it instead of the hardware maker, for example when phones use random private addresses on Wi-Fi.
What format does Cisco use for MAC addresses?
Cisco devices usually show three groups of four hex digits separated by dots, such as 001a.2b3c.4d5e.
Can it tell me the device maker?
No. It shows the OUI, the first three bytes, but has no vendor database. Locally administered addresses do not identify a maker anyway.