What is a MAC address OUI prefix?

The OUI (Organizationally Unique Identifier) is the first 24 bits, or 6 hex characters, of a MAC address. The IEEE assigns OUI blocks to manufacturers, so the prefix uniquely identifies who made the network interface.

Can I look up any MAC address format?

Yes. This tool accepts MAC addresses with colons (AA:BB:CC:DD:EE:FF), hyphens (AA-BB-CC-DD-EE-FF), dots (AABB.CCDD.EEFF), or no separator at all (AABBCCDDEEFF). All formats are normalized automatically.

Why does the lookup say Unknown for my device?

The tool uses a curated offline OUI database. Not every registered OUI block is included. For exhaustive lookups you can query the IEEE's public registry at standards.ieee.org/regauth/.

Network

MAC Address Vendor Lookup

Paste any MAC address to instantly identify the manufacturer. All common formats accepted. Runs locally in your browser.

Runs locally
Works offline
No uploads

MAC vendor lookup

OUI to manufacturer

MAC Address Lookup

MAC Address

Lookups run on-device against a bundled OUI database. Nothing is uploaded.

About this tool

Every network interface, physical or virtual, ships with a 48-bit MAC address burned into hardware. The first 24 bits are the OUI (Organizationally Unique Identifier) block assigned by the IEEE to the manufacturer. Knowing the OUI lets you quickly identify what brand of device is on your network.

This tool normalizes your input, extracts the OUI prefix, and looks it up against a curated offline database of well-known manufacturers. Everything runs in your browser; nothing is sent to a server.

Accepted formats

Colon-separated: B8:27:EB:12:34:56
Hyphen-separated: B8-27-EB-12-34-56
Cisco dot notation: B827.EB12.3456
Plain hex: B827EB123456

Lowercase letters are accepted; the tool uppercases them automatically before lookup.

Tips

On Android, go to Settings > About phone > Status > Wi-Fi MAC address to find your device MAC.
On Windows, run ipconfig /all in Command Prompt and look for "Physical Address".
On macOS or Linux, run ifconfig or ip link show in the terminal.
If the result shows "Unknown", the OUI is either not in this offline database or the address is locally administered (bit 1 of byte 1 is set).
A MAC starting with an even second hex digit (0, 2, 4, 6, 8, A, C, E) is globally unique. An odd second digit means it is locally administered or randomized.

About the MAC Address Vendor Lookup

MAC (Media Access Control) addresses are 48-bit identifiers assigned to network interfaces. They appear in Wi-Fi packets, ARP tables, router client lists, and network scan output. The first three bytes form the OUI, a registered block that tells you which company manufactured the interface chip or device.

How OUI lookup works

The IEEE assigns OUI blocks to manufacturers in batches. A block might cover millions of devices from a single vendor, or a small allocation for a boutique hardware maker. When you enter a MAC address here, the tool strips separators, uppercases the string, slices out the first six hex characters (the OUI), and looks them up in an offline table of well-known assignments. The whole process takes under a millisecond and never leaves your browser.

Randomized and locally administered MACs

Modern Android devices (Android 10+) and iOS devices randomize the MAC address used for each Wi-Fi network by default. A randomized MAC has the second-least-significant bit of the first byte set to 1, which means its OUI will not match any real manufacturer. If you see "Unknown" for a phone or tablet, privacy MAC randomization is likely the cause. You can check your device's Wi-Fi settings to see the real hardware MAC.

Reading the output

The tool shows you the normalized 12-hex-character form of your MAC, the isolated OUI prefix, and the manufacturer name from the database. Use the Copy button to grab the vendor name for pasting into a report, ticket, or chat. If your OUI is not in the offline database, the tool returns "Unknown"; for comprehensive lookups you can cross-reference the public IEEE registry.

Frequently asked questions

What is a MAC address?

A MAC (Media Access Control) address is a 48-bit hardware identifier assigned to a network interface. It is written as 12 hex digits, usually grouped in pairs separated by colons or hyphens. Every Ethernet port, Wi-Fi chip, and Bluetooth radio has one.

What is an OUI?

The OUI (Organizationally Unique Identifier) is the first 24 bits of a MAC address, represented as the first 6 hex characters. The IEEE allocates OUI blocks to manufacturers, so the OUI tells you who made the network interface.

Why does my phone show an Unknown vendor?

If your phone uses MAC address randomization (default on Android 10+ and iOS 14+), the randomized MAC will not match any real manufacturer OUI. Disable randomization in your Wi-Fi settings to see the hardware MAC, which will return the actual vendor.

Is my MAC address sent to a server?

No. The OUI database is bundled with this page and loaded entirely in your browser. Your input never leaves your device.