MAC Address Lookup - Find Manufacturer

About This Tool

Identify the manufacturer behind any MAC address with this free lookup tool. Paste a MAC address in any format (colon-separated, dash-separated, or raw hex), and instantly discover the device vendor, OUI (Organizationally Unique Identifier), cast type (unicast or multicast), and administration type (universally or locally administered). Every network interface card (NIC) has a unique 48-bit hardware address burned in at the factory. The first 24 bits form the OUI, which is assigned by the IEEE to specific manufacturers. By looking up this prefix, you can determine who made the network device. This is invaluable for network auditing, troubleshooting unknown devices on your network, identifying IoT devices, and security investigations. This tool includes an embedded database of over 100 commonly encountered OUI prefixes covering major vendors like Apple, Samsung, Intel, Cisco, Dell, HP, Google, Amazon, Raspberry Pi Foundation, Ubiquiti, and many more. For entries not in the local database, the tool clearly indicates that the OUI is unrecognized rather than guessing.

How MAC Address Identification Works

A MAC (Media Access Control) address is a 48-bit identifier written as six pairs of hexadecimal digits (e.g., 00:1A:2B:3C:4D:5E). The IEEE (Institute of Electrical and Electronics Engineers) manages OUI assignments, granting each manufacturer a unique 24-bit prefix. When a company like Apple receives the OUI 00:1B:63, every device they produce with that prefix will start with those three octets. The remaining three octets are assigned by the manufacturer to individual devices, ensuring global uniqueness. This tool extracts the first three octets from your input, looks them up in its OUI database, and returns the registered manufacturer name.

Unicast vs. Multicast MAC Addresses

The least significant bit of the first octet determines whether a MAC address is unicast or multicast. If bit 0 is 0, the frame targets a single network interface (unicast). If bit 0 is 1, the frame targets a group of interfaces (multicast). Broadcast addresses (FF:FF:FF:FF:FF:FF) are a special case of multicast where all devices on the network segment receive the frame. In practice, nearly all manufacturer-assigned MAC addresses are unicast. Seeing a multicast bit set on a supposedly device-specific MAC address can indicate a misconfiguration or a virtual/software-defined interface.

UAA vs. LAA (Administration Types)

Bit 1 of the first octet indicates whether the address is universally administered (UAA) or locally administered (LAA). UAA addresses (bit 1 = 0) are assigned by the manufacturer using their IEEE-registered OUI and guaranteed to be globally unique. LAA addresses (bit 1 = 1) are assigned by a network administrator or software and override the burned-in address. Virtual machines, Docker containers, and privacy-focused operating systems frequently use LAA addresses. Modern mobile devices randomize their MAC addresses when scanning for Wi-Fi networks, generating LAA addresses to prevent tracking. If you see an LAA address, the OUI lookup may not be meaningful since the address was not assigned by the original hardware manufacturer.

Common Use Cases for MAC Lookups

Network administrators use MAC lookups to identify unknown devices connected to switches and access points. Security teams trace suspicious network activity back to specific hardware vendors. IoT deployments verify that expected device types are connecting to the network. Home users can check their router's connected device list to identify unfamiliar entries. During penetration testing, MAC vendor information helps fingerprint target networks. MAC lookups also assist in asset inventory management, helping organizations track which hardware brands are deployed across their infrastructure.

MAC Address Formats

MAC addresses can be written in several equivalent formats:

Colon notation: 00:1A:2B:3C:4D:5E (most common on Linux/macOS)
Dash notation: 00-1A-2B-3C-4D-5E (common on Windows)
Dot notation: 001A.2B3C.4D5E (used by Cisco IOS)
Raw hex: 001A2B3C4D5E (compact, no separators)

This tool accepts all of these formats and normalizes them for lookup. Case does not matter (0a and 0A are treated identically).

Frequently Asked Questions

Why does the lookup show "Unknown Manufacturer"?

The tool uses an embedded database of common OUI prefixes. If your MAC address belongs to a smaller manufacturer, a recently registered OUI, or a locally administered address, it may not be in the local database. You can cross-reference with the full IEEE OUI database at standards.ieee.org for comprehensive coverage. Locally administered addresses (LAA) intentionally bypass manufacturer OUI assignments and will not match any vendor.

Can a MAC address be changed or spoofed?

Yes. While the burned-in address (BIA) is set at the factory, most operating systems allow you to override it with a software-defined address. On Linux, tools like macchanger or the ip command can set any MAC address. On Windows, you can change it through Device Manager or registry edits. On macOS, the ifconfig command allows temporary changes. MAC spoofing is used for privacy, bypassing MAC-based access controls, and testing. The changed address will have its locally administered (LAA) bit set to 1 in compliant implementations.

What is MAC address randomization?

Modern smartphones and laptops randomize their MAC address when scanning for Wi-Fi networks. Instead of broadcasting the real hardware MAC, the device generates a random locally administered address for probe requests. iOS, Android, and Windows all enable this by default. This prevents retailers and advertisers from tracking your device movements across locations using your MAC address. The randomized address typically changes periodically and differs per network. When the device actually connects to a known network, some implementations use the real MAC while others maintain a persistent random address per SSID.

What is the difference between OUI and MAC address?

The OUI is the first half of the MAC address (first 3 octets, or 24 bits). It identifies the manufacturer or vendor who produced the network interface. The full MAC address (all 6 octets, 48 bits) is the complete hardware identifier. The second half is a serial number assigned by the manufacturer. Think of the OUI as the brand name and the full MAC as the serial number. The IEEE also assigns OUI-36 and MA-S (smaller) blocks to manufacturers who need fewer addresses, but the standard 24-bit OUI is by far the most common.

How do I find the MAC address of my device?

On Windows, open Command Prompt and type ipconfig /all, then look for "Physical Address" under your network adapter. On macOS, go to System Settings, then Network, then select your connection and look for "MAC Address" in the details. On Linux, run ip link show or ifconfig and look for "ether" followed by the address. On iPhones, go to Settings, then General, then About, and find "Wi-Fi Address." On Android, go to Settings, then About Phone, then Status, and find "Wi-Fi MAC address." Note that some devices show a randomized address by default for privacy.