MAC Address Vendor Lookup
Look up the manufacturer of a MAC address from the IEEE OUI registry (MA-L, MA-M, MA-S), see unicast/multicast and local bits. Lookups happen in your browser.
Colons, hyphens, dots or no separators are all accepted.
What is MAC Address Lookup?
This tool identifies the organisation a MAC address block was assigned to by the IEEE, such as a network card or phone manufacturer. It also shows the address in colon, hyphen and Cisco dot notation and decodes the two flag bits that tell whether the address is unicast or multicast and universally or locally administered.
How to use MAC Address Lookup
- Paste a MAC address or just its first 6 hex digits; colons, hyphens, dots or no separators all work.
- Press Look up.
- Read the vendor and the assigned block (e.g.
44:38:39/24), plus the formatted versions of the address. - If the address is locally administered, note the warning: no vendor can be identified for random MACs.
Example
44-38-39-ff-ef-57
Vendor: Cumulus Networks, inc · block 44:38:39/24 · 44:38:39:FF:EF:57 / 4438.39ff.ef57 · unicast, universally administered (UAA)
When to use MAC Address Lookup
Use it to identify unknown devices in a DHCP lease table, ARP cache or Wi-Fi client list. It cannot find a specific device or its owner, and modern phones and laptops use randomized, locally administered MACs for privacy, which have no vendor.
How MAC Address Lookup works
The site ships a copy of the IEEE MA-L (24-bit), MA-M (28-bit) and MA-S (36-bit) registries, generated from Wireshark's manuf file and split into 256 small files by the first byte. Only the file for your MAC's first byte is downloaded from algokit.dev, and the longest matching prefix wins, so a 36-bit MA-S assignment is preferred over the 24-bit block that contains it. Bit 0 of the first byte marks multicast, bit 1 marks a locally administered address.
Common Use Cases
- Figure out which device on your LAN is the printer or the smart TV from the router's client list.
- Check whether a MAC in a log belongs to a virtual machine vendor such as VMware or a cloud provider.
- Convert a MAC between colon, hyphen and Cisco dot formats.
- Recognise randomized private Wi-Fi addresses by the local-administration bit.
FAQs
Why does my phone's MAC show no vendor?
iOS, Android and Windows use randomized MAC addresses per network. These have the locally administered bit set and are not registered with the IEEE, so no manufacturer can be found.
Is my MAC address sent to a server?
No. Only the shard file for the first byte (e.g. /data/oui/44.txt) is downloaded from this site; the matching happens in your browser.
Can a MAC address reveal a device's location or owner?
No. It only identifies the manufacturer of the network interface, and it never leaves your local network segment anyway.
How current is the vendor list?
It is a snapshot of the IEEE registries taken when the site was built. Very recent assignments may be missing.