MAC Address Formatter
Paste one or many MAC addresses in any style. They are rewritten in the format you choose, and the first one is explained: vendor prefix, group or single, and its IPv6 link-local address.
Worked examples
Three styles of one address
00-1A-2B-3C-4D-5E
00:1a:2b:3c:4d:5e 001a.2b3c.4d5e 001a2b3c4d5e
Colon, dotted and plain forms.
Link-local address
00:1A:2B:3C:4D:5E
fe80::21a:2bff:fe3c:4d5e
ff:fe is inserted and the second bit of the first byte is flipped.
About MAC Address Formatter
A MAC address is a six byte hardware identifier, and every system writes it its own way. Linux and macOS use colons, Windows uses hyphens, network equipment from several vendors uses three groups of four digits separated by dots, and databases often hold twelve digits with nothing between them. When you copy a list from one place to another, the format rarely matches.
Paste your addresses one per line, in any style or letter case, and the whole list is rewritten in the format you choose. The first address is also explained: the vendor prefix (the first three bytes), whether it is a single device or a group address, whether it was set by the manufacturer or locally, the EUI-64 interface identifier and the IPv6 link-local address a device with that MAC would create.
How to use MAC Address Formatter
- Paste one MAC address per line, in any style.
- Choose the output format and letter case.
- Copy the converted list.
- Read the details for the first address in the panel below.
Common uses
- Cleaning a list of addresses from different tools
- Preparing addresses for a DHCP reservation file
- Working out the IPv6 link-local address of a device
- Recognising randomised addresses used by phones
Frequently asked questions
What is the vendor prefix?
The first three bytes, called the OUI, are assigned to a manufacturer by the IEEE. The tool shows the prefix. Looking up the company needs a registry list, which is not included.
What does a group address mean?
If the lowest bit of the first byte is set, the address is for a group of devices, such as multicast, instead of one device. The broadcast address ff:ff:ff:ff:ff:ff is the special case where every bit is set.
What is a locally administered address?
If the second lowest bit of the first byte is set, the address was assigned by software or an administrator, not by the manufacturer. Phones use random addresses of this kind when scanning for networks.
How is the IPv6 link-local address worked out?
The EUI-64 method inserts ff:fe in the middle of the MAC, flips the locally administered bit of the first byte and puts the result after fe80::. Some systems use random interface identifiers instead.
Which separators are accepted on input?
Colons, hyphens, dots, spaces or none, with or without a 0x in front, in any letter case.