MAC Address Vendor Lookup - Free OUI Finder

A MAC address vendor lookup tells you which company made a network device by reading the first three bytes of its MAC address, known as the OUI. Enter an address in colon, dash or plain format, click Lookup Vendor, and you get the manufacturer plus the address type. It suits network admins, students and anyone tracing an unknown device.

What Is a MAC Address Vendor and an OUI?

A MAC address vendor is the manufacturer registered for the first half of a device's hardware address. A MAC address has 48 bits, written as six pairs of hex digits such as B8:27:EB:12:34:56. The first three pairs are the Organizationally Unique Identifier (OUI), which the IEEE assigns to a manufacturer. The last three pairs are the device identifier, which the manufacturer assigns to each unit it builds.

Because the OUI is shared by every device a vendor produces under that prefix, matching it reveals who made the network card or chip. It does not reveal the exact model, the owner or the location. A vendor can also hold many OUIs, so Apple, Intel and Cisco each appear under dozens of prefixes.

Two bits that change the meaning

The first byte also carries two flags. The lowest bit says whether the address is unicast (one device) or multicast (a group). The next bit says whether the address is globally administered (assigned by the IEEE registry) or locally administered (set by software or the operating system). This lookup reports both flags, which is why some results show a vendor and others do not.

How to Use the MAC Address Vendor Lookup

You can check a vendor in a few seconds with the single field on this page. Follow these steps:

1. Find the MAC address of the device you want to identify (see the section on finding it below).
2. Click the MAC Address field and paste or type the value. Colons, hyphens, dots and plain hex all work, for example 00:1A:2B:3C:4D:5E or 001A2B3C4D5E.
3. Click Lookup Vendor.
4. Read the vendor name and OUI at the top of the result.
5. Check the table underneath for the address type, the administration type and, if you entered a full address, the device identifier.
6. Try a sample prefix such as B8:27:EB if you want to see how a result looks before using your own data.

You need at least the first six hex digits. If you enter fewer, the tool asks for the first 3 bytes of a MAC address. Entering only the OUI is fine, and in that case the table skips the full address and device identifier rows.

Worked Example: Looking Up B8:27:EB:12:34:56

Say your router's client list shows an unfamiliar device with the address B8:27:EB:12:34:56. You paste it into the field and click Lookup Vendor.

• OUI (First 3 Bytes): B8:27:EB
• Vendor / Manufacturer: Raspberry Pi Foundation
• Address Type: Unicast
• Administration: Globally Administered (IEEE)
• Device Identifier: 12:34:56

This tells you the device is a Raspberry Pi single-board computer, not a phone or a laptop. The first byte is B8, which is 10111000 in binary. The lowest bit is 0, so the address is unicast. The next bit is also 0, so it is globally administered. That points to a real, registered hardware address. Your next step is to ask whoever manages your network whether someone connected a Pi project, and to check the device's name and traffic in your router.

How Do You Read the Lookup Results?

Each row in the result answers one question about the device, and together they show how far you can trust the vendor name. This table explains each field.

What a good result looks like

A good result shows a named vendor, a unicast address and a globally administered flag. That combination means the address came from a manufacturer's registered block and identifies one real network interface.

What a poor result looks like and how to fix it

• Vendor not found with a globally administered flag: the prefix may be missing from this lookup's coverage. Check the full IEEE OUI Registry linked under the result.
• Locally administered flag: the address was generated by software. Phones and laptops often do this on purpose for Wi-Fi privacy, and virtual machines and containers do it too. No vendor is expected, so identify the device by its hostname, IP address or switch port instead.
• Multicast or broadcast: the value is a group or all-ones address (FF:FF:FF:FF:FF:FF), not a single device. Look for the real source address in your capture or log.

How Do You Find the MAC Address of a Device?

You find a MAC address in the network settings of the device or in your router's client list. These are the usual places:

• Windows: run ipconfig /all in Command Prompt and read the Physical Address line.
• macOS and Linux: run ip link on Linux or ifconfig on macOS and read the ether or link/ether value.
• Other devices on your network: run arp -a to list neighbors, or open the connected devices page in your router.
• Packet captures: Wireshark shows source and destination addresses in the Ethernet header, and you can paste those into the field.

Note that a MAC address only exists on your local network segment. The address you see for a website or remote server belongs to a router on the path, not to that server. If you need information about a remote host, use its IP address with a tool such as ASN lookup instead.

Who Uses a MAC Vendor Lookup and When?

A MAC vendor check is the right tool whenever you have a hardware address and need to know what kind of device it is. Typical situations include:

• Finding rogue devices: your switch or router lists a client you do not recognize. A vendor of Espressif suggests a smart plug or hobby board, while Apple suggests a phone or laptop.
• Network audits: you are labeling an inventory spreadsheet and want a manufacturer next to each address.
• Troubleshooting: two devices appear to share a connection problem, and you want to know whether they use the same network chip family.
• Virtual machine checks: prefixes such as 00:50:56 (VMware) and 08:00:27 (Oracle VirtualBox) quickly tell you a host is virtual.
• Learning networking: students can see how OUIs, unicast flags and the local administration bit work on real values.

After you identify a device, you may want to trace its IP address. The My IP Address page shows your own public address, and Domain to IP resolves a domain name to its IP. For several IPs at once, Bulk IP Lookup handles up to 20 addresses, though it works with IP addresses, not MAC addresses.

Best Practices, Common Mistakes and Troubleshooting

Most wrong or empty results come from input problems or from expecting too much from a prefix. Keep these points in mind.

Check the input first

• Copy the address exactly. Swapping 0 and O, or 8 and B, changes the OUI and returns the wrong vendor or none.
• Do not paste an IP address. A value like 192.168.1.10 contains only decimal digits and dots and is not a MAC address.
• Do not paste an IPv6 address. It is longer and uses a different structure.
• Remove extra text such as labels or ports. The tool strips separators, but unrelated letters from A to F can be read as hex digits.

Interpret the vendor carefully

• The vendor is the maker of the network chip or card, which may differ from the brand on the box. A laptop sold by one company can report the chipmaker, such as Intel.
• Consumer routers often reuse chips from several suppliers, so two units of the same model can show different vendors.
• Treat the result as a clue and combine it with the hostname, IP address and connection time before taking action such as blocking a device.

When a result looks wrong

If the vendor name surprises you, first check whether the address is locally administered. Next, compare the prefix with the official registry. If the device is on your own network, confirm by reading the MAC from the device's own settings, because some devices rotate their Wi-Fi address per network.

Limitations and Accuracy Notes

This lookup matches prefixes against a list of commonly seen vendors, so very new, rare or small manufacturers may return Not found even when the address is valid. In that case, search the full IEEE OUI Registry through the link shown below each result. Longer private blocks assigned by the IEEE to small companies are also not split out here.

A vendor match also does not prove who owns the device, and it cannot tell you the model or whether the address has been spoofed. Anyone can change a MAC address in software. Use the result as one data point in an investigation, not as proof of identity.

If you want more tools for investigating hosts and networks, browse the Network and IP tools collection, or use DNS Lookup to inspect the records behind a domain.

Paste your address into the MAC Address field above and click Lookup Vendor to see the manufacturer, address type and administration flag in one view, then use those clues to decide what to do with the device.