MAC Address Generator

Generate random MAC addresses with configurable vendor OUI prefixes and format options (colon, dash, dot).

Tested tool guide Tested browser tools Checked August 16, 2026

What MAC Address Generator does and how it behaves

Choose a vendor OUI prefix and an output notation to produce random 48-bit MAC address text for test data, configuration samples, or documentation. The selected OUI occupies the first three octets, while the remaining three octets vary randomly. Colon and dash styles separate individual octets; dot style groups the hexadecimal digits in blocks of four. The important surprise is that a generated address is only a candidate value. It is not checked against devices on your network, guaranteed to avoid collisions, or proof that a device belongs to the organization associated with the prefix.

How the result is produced

OUI and random suffix

A MAC-48 address contains 12 hexadecimal digits arranged as six octets. When an OUI is configured, the generator preserves its six hexadecimal digits as the first three octets and randomizes the final three octets. The chosen prefix therefore defines a family of possible addresses, not a repeatable conversion. Generating again with unchanged settings can produce a different suffix.

Notation selection

The format option changes the written representation, not the underlying 48-bit value. Colon form is shaped like AA:BB:CC:DD:EE:FF, dash form like AA-BB-CC-DD-EE-FF, and dot form like AABB.CCDD.EEFF. Each notation contains the same 12 hexadecimal digits. Select the grouping required by the configuration file, command, parser, or test fixture that will consume the generated address.

Good uses

Populate parser tests with MAC-48 strings in colon, dash, and dotted forms, especially when the parser must accept one notation and reject another.
Create placeholder addresses for network documentation, screenshots, sample configuration files, or support instructions while keeping every example under the same selected OUI.
Prepare candidate addresses for an isolated lab, emulator, or network simulation where multiple syntactically valid values sharing a controlled prefix are needed.

Limits and checks

Random generation does not inspect the local network or an inventory database. A generated suffix can match an address already in use, so collision checking remains a separate task.
Selecting a vendor OUI makes the text resemble an address from that allocation, but the generated suffix is arbitrary. It does not identify a real product, interface, or serial record.
Separators do not determine whether an address is unicast, multicast, universally administered, or locally administered. Those properties come from bits in the address, not from colon, dash, or dot formatting.

Common questions

Can I assign a generated address to a real device?

Not automatically. A generated value may be usable in a controlled environment, but first check for collisions and follow the address policy of the device, platform, and network. Choosing a registered vendor OUI does not grant authority to allocate addresses from that organization's space. For managed deployments, use an approved locally administered addressing plan rather than treating random output as guaranteed unique.

Does the OUI prove which company made a device?

No. An OUI can associate the prefix with an organization responsible for that allocation, but this generator combines the prefix with a random suffix. The result is not evidence that a corresponding device exists or that the organization manufactured it. Real interfaces can also use reassigned, virtual, spoofed, or locally administered addresses, which limits vendor conclusions drawn from a displayed MAC address.

References and verification

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