MAC Address Generator

About this tool

Generate random MAC addresses for testing, or look up which vendor a MAC address's first three bytes (the OUI, Organizationally Unique Identifier) belong to. "Locally administered" addresses are recommended for test/fake MACs since that bit guarantees the address won't collide with a real, factory-assigned one from any vendor.

The vendor lookup checks against a curated list of well-known vendors (Apple, Samsung, Intel, Cisco, Raspberry Pi, common virtualization platforms, and more) — not the full IEEE OUI registry, which has tens of thousands of entries.

Frequently asked questions

What does "locally administered" mean?

Every MAC address has a bit that marks it as either "universally administered" (factory-assigned by the hardware vendor, globally unique) or "locally administered" (assigned by software/an administrator, e.g. for a VM or test device). Generating a locally administered address is the standard way to create a fake MAC that's guaranteed not to collide with a real vendor's range.

What does "multicast" mean?

Another bit marks whether a frame sent to this address is meant for one device (unicast) or a group of devices (multicast). Real network interface cards almost always use unicast addresses — leave this unchecked unless you specifically need a multicast-style address.

Why doesn't the vendor lookup recognize my MAC?

This tool only checks a curated shortlist of common vendors, not the full IEEE OUI registry (which has 40,000+ entries and would need to be downloaded in full to search offline). If your MAC isn't in the shortlist, it doesn't mean the OUI is invalid — just that it isn't one of the common vendors covered here.