Free Online MAC Address Formatter
Convert MAC addresses between colon, hyphen, dot, and plain formats.
Accepts 00:1A:2B:3C:4D:5E, 00-1A-2B-3C-4D-5E,
001A.2B3C.4D5E, or 001A2B3C4D5E.
A MAC address is 48 bits, written as six hexadecimal bytes. The first three bytes form the OUI, which identifies the manufacturer; the last three are assigned to the interface.
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About the MAC Address Formatter
A MAC address is a 48-bit hardware identifier, normally written as six hexadecimal bytes. Different systems expect different punctuation: Windows and Linux commonly use colon-separated pairs, some Windows tools use hyphens, Cisco devices use four-digit dotted groups, and scripts often want a plain twelve-character string. This formatter accepts any of those inputs and produces every common representation, plus a byte array for use in code.
The accepted input formats
- Colon: 00:1A:2B:3C:4D:5E
- Hyphen: 00-1A-2B-3C-4D-5E
- Cisco dotted: 001A.2B3C.4D5E
- Plain: 001A2B3C4D5E
- Spaced: 00 1A 2B 3C 4D 5E
Separators are ignored and the remaining characters must be exactly twelve hexadecimal digits. Any other character, a missing digit, or an extra digit is rejected. The input is not case-sensitive, so uppercase and lowercase hex letters are treated the same way.
Colon, hyphen, dotted, and plain forms
The colon form is the most common presentation in documentation, network traces, and Linux configuration. The hyphen form appears in Windows tools and some DHCP interfaces. Cisco's dotted form groups the twelve hex digits into three blocks of four, which is easier to read on routers and switches. The plain form contains no separators and is convenient for APIs, database keys, and command-line arguments that dislike punctuation.
Byte arrays for programming
Many languages represent a MAC address as an array of six bytes. The byte array output uses the form
[0x00, 0x1A, 0x2B, 0x3C, 0x4D, 0x5E], which can be pasted into C, C++, Java, JavaScript, or Python
with only small syntax adjustments. Keeping the values in hexadecimal avoids conversion mistakes and makes the
relationship to the printed address obvious.
The OUI and the interface bits
The first 24 bits are the Organizationally Unique Identifier, assigned to a manufacturer. The last 24 bits are assigned by that manufacturer to a specific interface. The first octet also carries two flag bits: the multicast bit and the locally administered bit. This formatter reports both, which helps distinguish a normal globally administered unicast address from a virtual machine, a randomized Wi-Fi address, or a multicast group address.
Frequently asked questions
Does formatting change the address?
No. All outputs represent the same 48 bits. Only punctuation, letter case, and grouping change.
What does locally administered mean?
That bit is set when the address was assigned by software rather than burned in by the manufacturer. Virtual machines, containers, and privacy features often use locally administered addresses.
Can I format EUI-64 addresses?
No. This tool is limited to 48-bit MAC addresses. An EUI-64 identifier has sixteen hexadecimal digits and is not accepted.