What is a MAC address converter?
A MAC address is written differently on almost every system. Windows uses hyphens, Linux uses colons, Cisco devices use three groups of four digits with dots, and some databases store it with no separator at all. They all describe the same 48 bits.
This converter reads a MAC address in any of these styles and rewrites it in the one you need, so you can paste an address from a switch into a Windows tool, or clean up a long list in one go.
How to use the MAC Address Converter
Type or paste the addresses into Enter MAC Addresses, one per line. You can mix formats in the same list. Click Copy Example if you want a sample to paste in and try.
Under Options, pick the Output format you need, choose UPPER or lower case letters, and tick Remove duplicates if your list repeats addresses.
The result appears below the form. From then on it follows your changes, so you can edit the list or switch the output format and watch the table update. An entry that is not a valid MAC address is marked in red instead of stopping the conversion.
The MAC Address and Converted columns are always shown. Tick or untick boxes in Show Columns to also see every other format, the OUI, whether the address is unicast or multicast, whether it is universal or local, the decimal value, EUI-64 and the IPv6 link-local address. On a phone or tablet that row slides sideways.
Copy puts the whole table on your clipboard and Download saves it as a CSV file, using only the columns you ticked. Copy List under the table copies just the converted addresses, one per line. Clear All empties the box and hides the result.
MAC address formats
The same address, 00:1A:2B:3C:4D:5E, written in each format the tool supports:
| Format | Where you see it | Example |
|---|---|---|
| Colon | Linux, macOS, most network gear | 00:1A:2B:3C:4D:5E |
| Hyphen | Windows, IEEE standard | 00-1A-2B-3C-4D-5E |
| Cisco dotted | Cisco IOS and IOS-XE | 001a.2b3c.4d5e |
| Huawei hyphen | Huawei and H3C | 001A-2B3C-4D5E |
| No separator | Databases and some APIs | 001A2B3C4D5E |
| Space | Some logs and documents | 00 1A 2B 3C 4D 5E |
| 0x prefix | Programming and hex dumps | 0x001A2B3C4D5E |
Whatever the format, the letters can be upper or lower case. They mean the same thing.
How the address is read
The tool takes out the separators and checks that what is left is exactly 12 hex digits (or 16 for an EUI-64 address). It also accepts octets written with one digit, such as 0:1:2:3:4:5, which some Linux tools print. It then builds each output format from the same six bytes.
The first byte also holds two flags. The lowest bit says multicast (1) or unicast (0). The next bit says locally administered (1) or universally administered (0). That is why virtual machine and container addresses often start with 02.
Example: from MAC address to EUI-64 and IPv6
00:1A:2B:3C:4D:5E becomes the EUI-64 00:1A:2B:FF:FE:3C:4D:5E when FF:FE is added in the middle. Flipping the universal/local bit of the first byte (00 becomes 02) gives the interface ID of the IPv6 link-local address fe80::21a:2bff:fe3c:4d5e.
When it helps
Use it to move a MAC address between a Cisco switch and a Windows or Linux tool, to write ACLs and DHCP reservations in the format your device expects, to clean a MAC list from a spreadsheet or inventory before you import it, and to work out the IPv6 address a device will give itself.
To check the IP address that goes with a device, use the IP Class & Type Detector. To plan the network the device sits in, use the IPv4 Subnet Calculator.