Rewrite a MAC in any format, read its bits, and get its EUI-64 and IPv6 link-local address
Runs in your browser. Nothing you type is sent anywhere. Checked against sources on 17 Oct 2026.A MAC address is 48 bits, usually written as 6 pairs of hex digits. This converter reads it in any notation, writes it with colons, hyphens, Cisco dots or none, reads its multicast and local bits, and builds the Modified EUI-64 identifier and fe80:: link-local address that IPv6 makes from it.
Paste the MAC address in any form: colons, hyphens, Cisco dots or 12 digits.
Every notation appears at once, in capitals or small letters, each with its own Copy button.
Read whether it is unicast or multicast, and universal or locally administered.
Copy the Modified EUI-64 interface ID or the fe80:: link-local address for IPv6.
Every network tool prints MAC addresses its own way: Linux and macOS use colons, Windows uses hyphens, Cisco switches group four digits with dots, and databases often store 12 bare digits. Paste any of them, or an 8-byte EUI-64, and get all the others at once, in capitals or small letters.
What the bits say. The first byte carries two flags, as RFC 7042 describes:
| Bit of the first byte | Off | On |
|---|---|---|
| Group, value 01 | Unicast: one device | Multicast or broadcast |
| Local, value 02 | Universal: assigned by the manufacturer | Locally administered: set by software |
A second hex digit of 2, 6, A or E means a locally administered unicast address, as used by virtual machines, Docker and phones that randomise their MAC per network. The page also names the special blocks: broadcast FF-FF-FF-FF-FF-FF, 01-00-5E IPv4 multicast, 33-33 IPv6 multicast, and IANA's 00-00-5E range with its documentation addresses.
IPv6 from a MAC. Without privacy extensions, an IPv6 host builds its interface identifier from its MAC by RFC 4291 Appendix A: insert FF-FE between the third and fourth bytes and flip the Local bit. So 00:00:5E:00:53:01 becomes 0200:5eff:fe00:5301, and the link-local address is fe80::200:5eff:fe00:5301. Add your /64 prefix for the global address, or paste an IPv6 address to read back the MAC inside it.
Random MACs. Generate locally administered unicast addresses for test networks; they cannot collide with a manufacturer's address.
The vendor name behind a MAC is not shown, because that needs the IEEE registry. Every conversion was checked against 400 addresses computed separately with Python's ipaddress module. Nothing you paste leaves the browser.
Paste the MAC in any notation, such as 00:1A:2B:3C:4D:5E or 00-1A-2B-3C-4D-5E, and the Cisco form appears at once: three groups of four hex digits separated by dots, 001a.2b3c.4d5e. Cisco IOS prints it in small letters, and the copy button takes it exactly as shown.
RFC 4291 inserts FF-FE between the third and fourth bytes of the MAC and flips the second-lowest bit of the first byte, giving a 64-bit interface identifier. The link-local address is fe80:: followed by it, so 00:00:5E:00:53:01 becomes fe80::200:5eff:fe00:5301.
A MAC whose first byte has the 02 bit set, which makes the second hex digit 2, 6, A or E. Software assigned it rather than the manufacturer: virtual machines, containers, bonded interfaces and phones that randomise their address per Wi-Fi network all use such addresses.
Look at the lowest bit of the first byte: when it is 1, the second hex digit is odd and the address is a group address that many devices listen to. 01-00-5E addresses carry IPv4 multicast, 33-33 addresses carry IPv6 multicast, and FF-FF-FF-FF-FF-FF is the broadcast address.
Yes, when the address was built from a MAC without privacy extensions: its interface identifier then has ff:fe in the middle, as in fe80::200:5eff:fe00:5301. Paste the address and the MAC is rebuilt. Random privacy and stable-privacy addresses contain no MAC, and the page says so.
No. The first three bytes, the OUI, are shown, but naming the vendor needs the IEEE registry of several hundred thousand entries, which is not bundled. A locally administered or randomised MAC has no vendor at all, because software chose the number.
Rates and rules change; check the source before you rely on a figure.
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