What formats does this tool accept?

The tool accepts four common formats: colon-separated (AA:BB:CC:DD:EE:FF), hyphen-separated (AA-BB-CC-DD-EE-FF), Cisco dot notation (AABB.CCDD.EEFF), and plain hex without separators (AABBCCDDEEFF). Uppercase and lowercase are both accepted.

What is OUI and how does the vendor lookup work?

OUI stands for Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address assigned to a vendor by the IEEE. This tool includes a built-in table of common OUI prefixes. If the prefix is not in the table, "Unknown / Unregistered" is shown.

Is my MAC address sent to any server?

No. All processing happens entirely in your browser using JavaScript. No data is transmitted anywhere.

Why does the vendor show Unknown?

The built-in OUI table covers the most common vendors. The IEEE maintains a database of over 40,000 OUI entries. If the prefix belongs to a less-common manufacturer or is a locally administered address, it will show as unknown.

What is Cisco dot notation?

Cisco IOS groups the six octets into three pairs of four hex digits separated by dots, e.g. aabb.ccdd.eeff. This carries the same information as other formats but is specific to Cisco equipment output.

Can I format a locally administered or multicast MAC address?

Yes. The formatter works on any 48-bit value regardless of the unicast/multicast or locally/globally administered bits. The OUI lookup will simply return Unknown for locally administered addresses since they do not correspond to a registered vendor.

MAC Address Formatter

Name: MAC Address Formatter
Availability: InStock
Author: Nham Vu

Paste any MAC address in any common format and instantly see all four notation styles plus the vendor name from the OUI prefix.

Enter MAC Address

MAC Address (any format)

Accepts colon, hyphen, dot (Cisco), or plain hex

Try a sample

Enter a MAC address on the left to convert it

Copied!

Summary

Paste any MAC address in any common format and instantly see all four notation styles plus the vendor name from the OUI prefix.

How it works

Paste or type any MAC address into the input field.
The tool auto-detects the format: colon, hyphen, Cisco dot, or plain hex.
All four output formats are displayed at once.
The OUI (first 3 octets) is looked up in the built-in vendor table.
Click the copy icon next to any format to copy it to your clipboard.

Use cases

Normalize MAC addresses to a consistent format before storing them in a database.
Convert copy-pasted Cisco MAC addresses (dot notation) to the colon format used by Linux.
Quickly identify which vendor manufactured a device from its MAC address prefix.
Reformat MAC addresses for use in different operating systems and network tools.
Validate that a MAC address is correctly formed before using it in a configuration.

Frequently Asked Questions

Last updated: 2026-06-10 · Reviewed by Nham Vu