Eight notations at once
The same MAC address is written differently on every platform. Linux uses colons, Windows uses hyphens, Cisco gear groups four digits with dots, and config files sometimes run the digits together. Paste any of those shapes and the separators and spaces are stripped, the twelve hex digits are read, and all eight notations come back. Pick the separator and the letter case you want and copy that one directly.
How the bit readout and the EUI-64 form are derived
The least significant bit of the first octet is the I/G bit: 0 means unicast and 1 means multicast. The second bit is the U/L bit: 0 means a globally unique address built on a vendor-assigned OUI, 1 means a locally administered address. The EUI-64 identifier and the IPv6 link-local address are built by inserting ff:fe in the middle and flipping the U/L bit, the method in the appendix of IETF RFC 4291. Checked October 2026.
Limits and what it will not do
Vendor names are not looked up. The OUI registry holds tens of thousands of entries and keeps changing, so any copy baked into a page goes stale. Only 12-digit MAC-48 values are handled; 16-digit EUI-64 input is rejected. Guidance has also moved toward random interface identifiers for IPv6, so treat the link-local address here as a reference for the older derivation only.
Frequently Asked Questions
Yes. A MAC address is a 48-bit value, and colons, hyphens, dots and letter case are only differences in how people write it. This tool reads them all as one value and shows the eight notations side by side.
It means the address is locally administered rather than built on a vendor-assigned OUI. You see it often on virtual machines and with randomised MAC features.
The OUI registry runs to tens of thousands of entries and keeps changing, so a copy stored in a page would soon be wrong. The first three octets are shown so you can look them up in the official registry.