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Layer 2

MAC Vendor (OUI)

Paste a MAC address in any format and get the manufacturer registered for its OUI (local IEEE database), plus an analysis of the U/L bit (locally administered or random?) and the I/G bit (unicast vs multicast).

Accepts any separator (:, -, . or none). The first 6 hex digits (the OUI) are enough.

The manufacturer is looked up in a local IEEE OUI database that ships with the page; nothing is sent to any server.

redzilla.cl — oui 
Enter a MAC to identify the manufacturer.

Local IEEE OUI database · everything runs in your browser · no sign-up · nothing leaves your browser.

How it works

The tool identifies the manufacturer of a device from the OUI of its MAC address: the first 6 hexadecimal digits, which the IEEE registry assigns to each company. It accepts the MAC in any format (3C:5A:B4:01:23:45, 3c5a.b401.2345 or just 3C5AB4), normalizes it and looks the prefix up in an IEEE database that is downloaded together with the page.

Besides the vendor, it locally analyzes the two flag bits of the first octet defined in IEEE 802: the U/L bit (bit 1), which set to 1 marks a locally administered address, typical of the privacy MAC randomization in Android, iOS and Windows, and the I/G bit (bit 0), which distinguishes unicast from multicast. Quick rule: if the second hex digit is 2, 6, A or E, the MAC is locally administered and the vendor cannot be identified.

Example: what is that unknown device on my network?

  1. Copy the MAC your router shows, for example B8:27:EB:12:34:56, and paste it into the field.
  2. The OUI B8:27:EB is registered with the IEEE to the Raspberry Pi Foundation: the mystery device is a Raspberry Pi.
  3. The bits confirm it is a real MAC: first octet 0xB8 → U/L = 0 (universal) and I/G = 0 (unicast).
  4. If the MAC were DA:1B:44:... instead, the second digit A would reveal a randomized address: the vendor cannot be known.

Frequently asked questions

Why does the lookup find no vendor for my MAC?
The two most common causes: the MAC is randomized (locally administered, with a second digit of 2, 6, A or E), which modern phones do by default on every WiFi network, or the OUI belongs to a recent registration or a small block (MA-M/MA-S) not present in the database. In the first case no service can identify the manufacturer.
How many digits of the MAC do I need to identify the vendor?
The first 6 hexadecimal digits (3 octets), which form the OUI, are enough. The other 6 are the serial number the manufacturer assigns to each interface, so they add nothing to the identification and you can safely leave them out.
Can I find the exact device model from the MAC?
No: the IEEE registry only links the prefix to the company, not to products. A single OUI of a large vendor may cover routers, cameras and phones. To narrow down the model you need to combine the OUI with other clues: DHCP hostname, open ports or traffic fingerprinting.
Is the MAC I look up sent to any server?
No. The IEEE OUI database is downloaded as a file together with the page and the lookup runs in your browser; the bit analysis is local too. No MAC you type ever leaves your machine.
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Disclaimer We take great care to keep every tool accurate and review it thoroughly; even so, we can't guarantee it is free of errors or take responsibility for how the results are used. We recommend double-checking anything critical.
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