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MAC address formatter

Format a 48-bit MAC address and inspect its bytes and address flags.

MAC address workbench02:1A:2B:3C:4D:5E
Byte 1 · 8 bits00000010
Group / individual flagUnicast
Administration flagLocally administered (U/L = 1)

Flags come from the first byte. They do not identify a manufacturer.

Processed on your device

How it works & useful details

How it works & limits

Accepts six colon- or hyphen-separated hex pairs, three dotted groups, or twelve hexadecimal digits. Output preserves all 48 bits; it only changes the notation and letter case.

The low two bits of the first byte indicate group/individual and local/universal administration. These are bit flags, not evidence of a vendor or device identity. This tool does not perform vendor lookups, generate addresses, or determine whether an address is assignable.

Your working space

Explore the live view, then save copyable text and a downloadable file. Everything is calculated locally. Inputs are not stored; refreshing clears them.

These tools inspect address notation and ranges. They do not contact addresses, check availability or establish connectivity.

About this tool

MAC address formatter converts a 48-bit hardware address between common notations, such as colon-separated, hyphen-separated, and Cisco-style groups, and shows the individual bytes and address flags.

The address is parsed locally and the flags reveal whether the interface is locally administered or multicast, which is useful for OUI and virtualization work. Nothing is sent to a vendor lookup service.

How to use it

  1. Enter the MAC address in any common notation.
  2. Review the normalized and alternative formats.
  3. Inspect the byte breakdown and the address flags.
  4. Copy the notation your device or tool expects.

Worked example

02:1a:2b:3c:4d:5e in uppercase can be written as:

Colon:   02:1A:2B:3C:4D:5E
Hyphen:  02-1A-2B-3C-4D-5E
Dotted:  021A.2B3C.4D5E
Plain:   021A2B3C4D5E

The first byte, 0x02, is 00000010 in binary. Its lowest bit (0) marks an individual, unicast address. The next bit (1) marks it as locally administered, meaning it was set by software rather than burned in by a manufacturer.

Which format each system expects

Linux and macOS tools print colon-separated lowercase. Windows uses hyphens and uppercase. Cisco equipment uses dotted groups of four. Inventory and DHCP reservation spreadsheets often use plain hex. Normalizing to one format before comparing lists avoids false mismatches between identical addresses.

Randomized MAC addresses, used by modern phones and laptops for Wi-Fi privacy, are locally administered. So if the second-lowest bit of the first byte is set, the address is probably not the device's hardware address. That makes it a hint, not proof: vendor identity cannot be determined from the flags alone, and this tool does not look up vendors.

Frequently asked questions

What do the address flags mean?

The two low bits of the first byte indicate whether the address is unicast or multicast and whether it is globally unique or locally administered.

Does it identify the hardware vendor?

No. No OUI database is queried; the tool only formats and inspects the address itself.

Are 64-bit EUI-64 addresses supported?

This formatter targets 48-bit EUI-48 hardware addresses.

Which input formats are accepted?

Six hex pairs separated by colons or hyphens, three dotted groups of four hex digits, or twelve hex digits without separators, in either letter case.