MAC Address Lookup

Server assisted New Internet & Network

Reads a MAC address in any common spelling (colons, hyphens, Cisco dots, bare hex, a six-digit prefix or a 64-bit EUI-64), checks it in your browser, then looks up the most specific matching block (MA-L, MA-M or MA-S) in the Mutqan server's copy of the IEEE Registration Authority tables. It also decodes the two flag bits of the first byte: unicast or multicast, and universally or locally administered — the mark of the randomised private addresses phones and laptops now use, and of virtual machine and container interfaces, which no manufacturer table can name.

Privacy: The domain, address or URL you enter is sent from the Mutqan server to the public data service named on this page (a registry, a resolver, a certificate log or a measurement network). Nothing is stored.

How do you find the manufacturer of a MAC address?

The leading 24, 28 or 36 bits of a MAC address are a block that the IEEE Registration Authority assigned to an organisation (MA-L, MA-M or MA-S), so looking up the longest matching prefix in the IEEE's public registry names the organisation that registered it, usually the maker of the network interface. Two bits of the first byte change the answer (RFC 7042): a set group bit means a multicast address, and a set local bit means software chose the address, which is how phones and laptops randomise their Wi-Fi addresses for privacy (RFC 9724) and how virtual machines and containers get theirs. No manufacturer can then be named, and networks that recognise devices by address have to allow for it (RFC 9797).

How to use MAC Address Lookup

  1. Paste a MAC address from a router's client list, a network log or a device label, in any spelling; the first six hex digits alone are enough for a classic OUI.
  2. Press Look up vendor.
  3. Read the manufacturer and block type, then the first-byte bits: a locally administered address has no manufacturer by design.

MAC Address Lookup features

  • Accepts every common spelling: colons, hyphens, Cisco dots, bare hex, spaces, a six-digit vendor prefix or a 64-bit EUI-64, checked in your browser before any request
  • The most specific IEEE block that matches: MA-S (36-bit), then MA-M (28-bit), then MA-L (24-bit), with the registered organisation and its address
  • The two flag bits of the first byte decoded: unicast or multicast, and universally or locally administered
  • Locally administered addresses, the shape of randomised private Wi-Fi addresses as well as of virtual machine and container interfaces, recognised and explained instead of reported as unknown
  • The date of the IEEE table every answer comes from, so a missing new block is understood
  • The address details still shown from the address itself if the vendor table is unavailable

Inputs and outputs

Inputs

  • MAC address: 12 hex digits in any common spelling (AA:BB:CC:DD:EE:FF, AA-BB-CC-DD-EE-FF, AABB.CCDD.EEFF, AABBCCDDEEFF), 16 for an EUI-64, or the first 6 for a vendor prefix.
  • Mixed separators (AA:BB-CC) and characters other than hex digits are refused with a plain explanation before any request.

Outputs

  • Summary: manufacturer, registry block, administration (universal or local) and cast (unicast or multicast).
  • Details: normalised address, length, matched prefix, registered address, whether it looks randomised, the registry and the table date.
  • The first byte bit by bit, and a short reading of what the result means.

MAC Address Lookup example

A Raspberry Pi's Ethernet address

Input:

MAC address: dc:a6:32:12:34:56

Output:

Manufacturer: Raspberry Pi Trading Ltd · Registry block: MA-L · Administration: Universal (manufacturer-assigned) · Cast: Unicast
Normalised address: DC:A6:32:12:34:56 · Length: 48-bit MAC (EUI-48) · Matched prefix: DC:A6:32 · Registered address: Maurice Wilkes Building, Cowley Road Cambridge GB CB4 0DS · Randomised (private) address: No · Table date: 2026-10-10
First byte: 0xDC = 11011100 · I/G bit (lowest bit): 0: unicast, one interface · U/L bit (second-lowest bit): 0: universally administered, assigned by the manufacturer

How to read the MAC Address Lookup results

The manufacturer is the organisation that registered the block: usually the maker of the network chip or the device, sometimes a module supplier, a contract manufacturer or a virtualisation product.

"Not in the registry" for a universally administered address means a typo, a block newer than the table, or an address someone made up.

A locally administered unicast address (second hex digit 2, 6, A or E) was set by software: a randomised private Wi-Fi address, a virtual machine or container interface, or an address an administrator assigned.

A multicast address (first byte odd, such as 01:00:5E for IPv4 multicast, 33:33 for IPv6 multicast or FF:FF:FF:FF:FF:FF for broadcast) names a group of interfaces, not one device.

IEEE Registration Authority as the vendor of a six-digit prefix means the prefix is divided into smaller MA-M or MA-S blocks; enter the full address to find the holder.

When to use MAC Address Lookup

  • Identifying unknown devices in a router's DHCP client list or on an office Wi-Fi network.
  • Checking whether a device in network logs uses a randomised address before writing a MAC allow-list or a DHCP reservation for it.
  • Recognising virtual machine interfaces (VMware 00:0C:29, Hyper-V 00:15:5D, VirtualBox 08:00:27) in a network inventory.

Troubleshooting

  • A separator or digit error: use one separator throughout and only the digits 0–9 and letters A–F; the letter O and the digit 0 are a common mix-up.
  • A six-digit prefix is "not in the registry" or shows IEEE Registration Authority: the block is an MA-M or MA-S block, which only the full address can resolve.
  • A phone or laptop shows no manufacturer: it uses a private address for this network. Its real hardware address is in the device settings, or switch the private address off for that network.
  • "The vendor table is not available": the server could not load its copy of the IEEE table; the bit-level details are still correct, and a later try usually works.

Frequently asked questions about MAC Address Lookup

Why does my phone's MAC address show no manufacturer?

Current phones and tablets, and laptops with the option switched on, use a random "private" Wi-Fi address for each network, so they cannot be tracked from place to place. Such an address has the locally administered bit set, and no manufacturer table lists it by design. The real hardware address is still in the device's settings, usually under the Wi-Fi network's details or "About".

What do MA-L, MA-M and MA-S mean?

They are the IEEE's block sizes. MA-L (the classic OUI) is a 24-bit prefix covering about 16.7 million addresses, MA-M a 28-bit prefix covering about a million, and MA-S a 36-bit prefix covering 4,096. The smaller blocks are carved out of prefixes the IEEE itself holds, so they can only be found from a full address, not from the first three bytes alone.

Can a MAC address be traced to a person or a place?

No. The vendor names the company that registered the block, usually the maker of the network interface, not the owner of the device. MAC addresses also never travel across the Internet: they are only seen on the local network segment, so a website never receives yours.

Is the vendor always the brand of the device?

Not always. The block can belong to the maker of the Wi-Fi or Ethernet chip, a module supplier or a contract manufacturer, and virtual machines use their hypervisor's prefix (VMware's 00:0C:29, for example). Any address can also be changed in software, so the vendor is a hint, not proof.

How current is the vendor table?

The table is compiled from the IEEE Registration Authority's public MA-L, MA-M and MA-S lists, and every result shows the date the table was built. A block assigned after that date is reported as not found until the table is refreshed.

Is the MAC address I enter sent anywhere?

It is checked in your browser first, then sent to the Mutqan server, which looks it up in its own copy of the IEEE table. It is not passed to any third-party lookup service, and it is not stored.

Technical notes

An EUI-48 MAC address is six bytes. The leading 24, 28 or 36 bits identify the organisation that registered the block with the IEEE Registration Authority (MA-L, MA-M, MA-S) and the rest is assigned by that organisation. In the first byte, the lowest bit (I/G) marks a group (multicast or broadcast) address and the next bit (U/L) a locally administered one; RFC 7042 describes these bits and how the IETF uses IEEE 802 identifiers.

GET /api/v1/internet/providers/mac/:mac reads a table compiled from the IEEE's public MA-L, MA-M and MA-S CSV files (public/data/oui.v1.json), loaded once per server isolate from the site's own static files. The longest matching prefix wins, because MA-M and MA-S blocks are carved out of 24-bit prefixes the IEEE itself holds (8C:1F:64, for example). No third-party lookup service is called.

Randomised addresses (RFC 9724) set the U/L bit and clear the I/G bit, so they are locally administered unicast addresses that no vendor table lists. An IPv6 interface identifier built from a MAC (modified EUI-64) has the U/L bit inverted and therefore does not match the table as it stands.

Limitations and methodology

The table is a dated snapshot of the IEEE public lists: blocks assigned after its date are not found, and the separate CID registry for locally administered company identifiers is not included.

The vendor says who registered the block, not the brand on the device or its owner, and any MAC address can be changed in software.

A MAC address identifies an interface on a local network only; it reveals no location and is never seen by websites.

Security and privacy

The address is checked in your browser, then sent to the Mutqan server, which looks it up in its own copy of the IEEE table. No third-party service receives it, and it is not stored.

References