Updated · Built and checked by the PlinzoTools team, formulas tested against published sources
Generate random, well-formed MAC addresses for test data.
Click Generate to create new MAC addresses.
A MAC (Media Access Control) address is a 48-bit hardware identifier assigned to network interfaces. This tool generates random, well-formed MAC addresses for test data or examples, with the "locally administered" bit deliberately set so the generated addresses never collide with a real vendor-assigned address range.
Choose how many to generate and a separator style (colon or hyphen). Click Generate for a fresh batch.
6 random bytes are generated, with the first byte's second-lowest bit forced to 1 (the "locally administered" flag, per IEEE 802 addressing conventions) -- this marks the address as not from any real manufacturer's globally-assigned OUI block, making it safe and unambiguous as test data.
For generating random IP addresses alongside test MAC addresses, see the Random IPv4 Generator.
A MAC address is six bytes, written as twelve hexadecimal digits. In this tool the first byte is modified after being generated randomly: its lowest two bits are replaced so that the second-lowest bit is 1 (locally administered) and the lowest bit is 0 (unicast). The practical effect is that the second hexadecimal digit of every address is always 2, 6, A, or E. So a generated value might look like 3A:5C:91:0F:BE:27, where the first byte 3A ends in the digit A. The other five bytes are fully random. Digits are printed in uppercase with a leading zero where needed.
If the lowest bit of the first byte were 1, the address would denote a group or multicast destination, which is not valid as the address of a single network card. Forcing it to 0 keeps every result plausible as a device address. That is why you will never see, for instance, an address starting with 01 from this tool.
Choose how many addresses you need, from 1 to 200, pick a colon or hyphen separator, and click Generate. Colon style suits Linux, macOS, and most network device documentation. Hyphen style matches the way many Windows tools display physical addresses. The separator setting applies to freshly generated batches, so change it before clicking Generate rather than expecting the current list to be reformatted. You can copy the list or download it as a text file.
These addresses are fictional test values. Do not use them to bypass network access controls, to impersonate other devices, or to spoof filtering on a network you do not own or administer. Changing a real interface's address is a separate, device-specific operation that this tool does not perform, and some networks or policies forbid it. Also note that the tool does not produce vendor-prefixed addresses, so it cannot be used to mimic a particular manufacturer's range for lookup tests.
Uniqueness within a batch is not checked. With well over forty bits of randomness per address, a repeat is very unlikely, but you should deduplicate if your test needs a guarantee.
Extremely unlikely -- the locally-administered bit is deliberately set, which real vendor-assigned (globally unique) MAC addresses never have, so a generated address structurally can't match a genuine manufacturer-assigned one.
A flag bit in the first byte of a MAC address that IEEE 802 addressing conventions reserve for locally-assigned (non-vendor) addresses -- setting it is the standard way to generate a MAC address guaranteed not to collide with real hardware.
Yes -- both are common conventions (colons are more common on Unix-like systems, hyphens on Windows), and this tool supports either.
Because the first byte is forced to have the locally administered bit set and the multicast bit cleared, which leaves only those four possible values for the second hex digit.
No. The tool always sets the locally administered bit, so the results never carry a real manufacturer prefix.
The separator applies to the next batch you generate, so pick it first and then click Generate.
Reference: MDN Web Docs