MAC Address Formatter

Convert MAC addresses between colon, dash, dot, and bare hex formats with OUI lookup.

Tested tool guide Tested browser tools Checked August 16, 2026

What MAC Address Formatter does, with a checked example

MAC Address Formatter rewrites the same 48-bit address as six colon-separated octets, six dash-separated octets, three dot-separated four-digit groups, or 12 bare hexadecimal digits. It also looks up the registration associated with the address prefix when a matching OUI record is available. The result does not change the address itself. The most common mistake is treating an OUI match as proof of the device manufacturer or model. It identifies a registered organization, which may be an interface vendor, an OEM supplier, or another assignee.

Worked example

A concrete input and expected output from the current implementation.

Input

00000c123456

Expected output

Colon: 00:00:0C:12:34:56
Dash: 00-00-0C-12-34-56
Dot: 0000.0C12.3456
Bare: 00000C123456
OUI: 00:00:0C - Cisco Systems, Inc.

The 12 hexadecimal digits split into octets as 00, 00, 0C, 12, 34, and 56. The first six digits form the 00:00:0C OUI registered to Cisco Systems, Inc.; changing separators or letter case does not change the underlying value.

How the result is produced

Separator normalization

The address characters are interpreted as hexadecimal. Removing the supported separators from 00:00:0C:12:34:56, 00-00-0C-12-34-56, or 0000.0C12.3456 leaves the same 12 digits. Output formatting regroups those digits as six two-digit octets, three four-digit groups, or one uninterrupted string. Hexadecimal letter case does not change the value. The address is processed in the browser and is not uploaded.

OUI interpretation

For a conventional OUI-based address, the first 24 bits are the first six hexadecimal digits, so 00000C123456 has the prefix 00000C. The lookup reports the registry organization associated with that prefix when a matching record exists. The remaining six digits are assigned within that organization's block; they do not encode a device model that the formatter can recover.

Good uses

Convert a dotted MAC address copied from a Cisco-style switch table into colon-separated form for a Linux command, inventory record, or configuration file.
Normalize dash-formatted addresses from Windows output and colon-formatted addresses from Unix output before comparing asset lists or removing duplicates.
Check the registered prefix assignee while investigating an unfamiliar interface observed in a DHCP lease, ARP table, packet capture, or access-control list.

Limits and checks

Successful formatting proves only that the hexadecimal structure can be normalized. It does not show that the address is reachable, currently assigned, unique on a network, or an individual rather than a group address.
Locally administered and privacy-randomized addresses need not identify a hardware vendor. A prefix lookup may therefore be absent or misleading for phones, laptops, virtual machines, containers, and software-created interfaces.
An OUI result names the organization associated with the registered prefix, not necessarily the company whose logo appears on the device. OEM sourcing, replacement adapters, and virtual interfaces can separate those identities.

Common questions

Do colons, dashes, dots, or uppercase letters produce different MAC addresses?

No. For the supported forms, separators only divide the same hexadecimal digits into readable groups, and A through F have the same numeric values in either case. For example, 00:00:0c:12:34:56 and 0000.0C12.3456 represent the same 48-bit value. Changing a digit, however, changes the address.

Does an OUI match identify the exact device?

No. An OUI match attributes a prefix to a registered organization. It does not reveal the device model, serial number, owner, location, or whether the address is currently active. A missing result also does not by itself make an address invalid, particularly when the locally administered bit is set or the relevant assignment is not represented by an OUI match.

References and verification

The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.