MAC address formatter
Every device and OS writes MAC addresses differently; this gives you all formats at once and reads the flag bits.
Loading the tool…
Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter mac address.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Lowest bit of the first byte: 0 unicast, 1 multicast. Next bit: 0 universal (IEEE OUI), 1 locally administered. Modified EUI-64: flip that bit, insert FFFE in the middle and append to fe80::/64.
Example
Inputs: MAC address = 00-1A-2B-3C-4D-5E. Result: Colon format: 00:1A:2B:3C:4D:5E; Cast type: Unicast; Administration: Universally administered (IEEE assigned).
00-1A-2B-3C-4D-5E
00:1A:2B:3C:4D:5E
Limits and caveats
- It does not name the vendor, since the IEEE registry is large and changes often; it shows the OUI prefix only.
- Modern phones use random, locally administered MACs for privacy, so they do not identify the real hardware.
Questions about this tool
Is there a difference between colon and hyphen formats?
No, the value is the same. Linux and macOS use colons, Windows and IEEE use hyphens, and Cisco uses three dotted groups.
What does locally administered mean?
The second bit of the first byte is 1: software set the address, not the maker, as with random privacy MACs.
What is the EUI-64 address?
An older way to derive an IPv6 interface id from the MAC; many systems now use random ids instead.