how do I find out who made a device from its MAC address?

Enter the MAC address, or just its first three octets. The tool checks them against a bundled list of common vendor OUI assignments and reports the manufacturer name if there's a match.

what does locally administered mean for a MAC address?

It means the address was set by software or an administrator rather than assigned by the hardware vendor's registered OUI. The tool detects this from the second-least-significant bit of the first octet, a common pattern for VMs and randomized addresses.

why doesn't my MAC address show a vendor?

The bundled dataset covers roughly 125 common OUIs, not the IEEE's full registry of tens of thousands of assignments, so a legitimate but less common vendor prefix correctly reports as not found instead of a guessed result.

how can I tell if a MAC address is multicast?

Check the Cast row: it reads the least-significant bit of the first octet, which IEEE 802 addressing reserves as the multicast/group flag, so any odd first-octet value indicates a multicast or group address.

MAC Address Lookup

Find the vendor of a MAC address from a bundled set of common OUI prefixes, locally.

Local, Runs entirely in your browser, your data never leaves your device.

Loading tool…

Find the vendor behind a MAC address prefix

This tool reads the first three octets of a MAC address, its OUI, and checks them against a bundled, curated list of common vendor assignments, roughly 125 entries rather than the IEEE's full registry of tens of thousands. It also reports whether the second-least-significant bit of the first octet marks the address as locally administered, and whether the least-significant bit marks it as multicast. It's useful for identifying what kind of device a MAC in a DHCP lease list or packet capture belongs to, with the lookup happening as a table match in your browser, no external API call.

How to use the MAC Address Lookup

Paste a full MAC address, or just the first three octets, the OUI.
Read the Vendor field for a match from the bundled dataset.
Check the Administration row to see if the address is locally administered or a real OUI assignment.
Check the Cast row to see if the address is unicast or multicast.

The dataset is a curated subset of well-known hardware, virtualization and IoT vendor OUIs, not the full IEEE registry, so a valid but less common vendor prefix may correctly show as not found rather than an incorrect guess.

The locally-administered and multicast flags are read directly from bit positions in the first octet, per IEEE 802 addressing rules, so they work for any address, including ones the vendor lookup itself can't identify.

Frequently asked questions

how do I find out who made a device from its MAC address?: Enter the MAC address, or just its first three octets. The tool checks them against a bundled list of common vendor OUI assignments and reports the manufacturer name if there's a match.
what does locally administered mean for a MAC address?: It means the address was set by software or an administrator rather than assigned by the hardware vendor's registered OUI. The tool detects this from the second-least-significant bit of the first octet, a common pattern for VMs and randomized addresses.
why doesn't my MAC address show a vendor?: The bundled dataset covers roughly 125 common OUIs, not the IEEE's full registry of tens of thousands of assignments, so a legitimate but less common vendor prefix correctly reports as not found instead of a guessed result.
how can I tell if a MAC address is multicast?: Check the Cast row: it reads the least-significant bit of the first octet, which IEEE 802 addressing reserves as the multicast/group flag, so any odd first-octet value indicates a multicast or group address.