Paste a MAC address in any format, with colons, hyphens, dots or no separators, and get it back in every common format with a copy button for each. The converter also reads the two flag bits in the first byte, so you can tell a manufacturer address from a random one set by a phone or a virtual machine, and shows the IPv6 link-local address the interface would build from it.
Table of Contents
MAC address formats
A MAC address is 48 bits written as 12 hexadecimal digits. Linux and macOS print it with colons (00:1a:2b:3c:4d:5e), Windows with hyphens (00-1A-2B-3C-4D-5E), and Cisco switches in three dotted groups (001a.2b3c.4d5e). They are the same address; only the notation differs.
What the first byte tells you
The lowest bit of the first byte is the I/G bit: 0 means one network card, 1 means a multicast group. The next bit is the U/L bit: 0 means the address was assigned by the manufacturer, whose prefix (the OUI) is the first three bytes; 1 means it was set locally by software.
Phones and laptops now use random, locally set MAC addresses on Wi-Fi for privacy, and hypervisors give virtual machines local addresses too, so a vendor lookup will not find those.
MAC addresses and IPv6
With SLAAC, an interface can build its IPv6 interface ID from its MAC address using EUI-64: insert FF:FE in the middle and flip the U/L bit. The result, after fe80::, is the link-local address. Many systems now use random or stable private interface IDs instead, so the real address may differ.
MAC Address Converter at a glance
Official documentation: IEEE Registration Authority (OUI), RFC 4291 (IPv6 addressing, EUI-64).
Related guides: pfSense VLAN Setup with a Managed Switch: Easy 2026 Guide · VPN MTU Fragmentation: Proven Fixes for Slow VPN Throughput.
Frequently asked questions
Can I find the manufacturer from a MAC address?
Yes, if the U/L bit is 0: the first three bytes are an OUI registered with the IEEE, and the public IEEE listing names the company. Locally set and random addresses have no manufacturer.
Why does my phone show a different MAC on each Wi-Fi network?
Android and iOS use a private, randomised MAC address per network by default, so networks cannot track the device. You can switch it off per network in the Wi-Fi settings.
Are MAC addresses unique?
Manufacturer addresses are meant to be unique, but software can change them and virtual machines can be cloned, so duplicates do happen. They only need to be unique on the same local network.