MAC Address Generator
Generate random 48-bit MAC addresses with explicit local/universal and unicast/multicast bits, optional fixed prefixes and common output formats.
Set the address bits deliberately
The default sets the locally administered bit and clears the group bit in the first octet, producing local unicast addresses suitable for examples and controlled network configuration. Local multicast sets both low bits. Any-bit mode leaves both bits random.
The universal-bit option produces synthetic values, not manufacturer-issued addresses. No OUI registry lookup or manufacturer claim is made. Random generation uses crypto.getRandomValues and rejects duplicates within this batch; it cannot guarantee uniqueness across devices, previous batches or other generators.
Prefixes and available capacity
An optional prefix fixes up to five full octets, separated by colons or hyphens. For example, 02:12:34 leaves three random octets. The first fixed octet must agree with the selected address class; a conflicting prefix is rejected instead of silently rewritten.
Choose colon, hyphen, Cisco-style dotted or plain hexadecimal output, with optional uppercase. Generate up to 1,000 addresses. A five-octet prefix leaves only 256 possible values, so a larger request is rejected. These values are examples or configuration inputs, not a mechanism to assign hardware addresses automatically.
Reference
Questions & answers
Does a generated address identify a vendor?
No. The generator does not allocate OUIs. Use locally administered unicast values for controlled examples and check your network before assigning one.
Why is my prefix rejected?
Its syntax, first-octet class bits or remaining random capacity may conflict with your options. Change the class or shorten the fixed prefix.
Is my input uploaded?
No. Parsing and generation run in your browser. Engines and datasets load from this site; the tool does not store input or send it to a processing API.