OUI Lookup Tool
Look Up the Organizationally Unique Identifier of a MAC Address
Need to use OUI Lookup Tool right now?
The OUI is the IEEE-assigned manufacturer prefix baked into every MAC address — this extracts it directly and checks it against known vendor prefixes.
Normalized address
B8:27:EB:12:34:56
OUI (vendor prefix)
B827EB
Vendor
Raspberry Pi Foundation
Features
- Runs entirely in your browser
- Privacy-first — your data is never uploaded
- Real-time, instant results
- 100% free, no sign-up required
- Works on desktop, tablet, and mobile
- No installation needed
Who uses this tool?
About OUI Lookup Tool
Every network device — a phone, laptop, router, smart TV, IoT gadget — has a MAC (Media Access Control) address burned into its network hardware, and the first half of that address isn't random: it's an OUI (Organizationally Unique Identifier) officially assigned by the IEEE to the specific manufacturer that made the hardware.
This tool takes any MAC address, extracts its OUI (the first three octets), and looks it up against a curated set of well-known, verified manufacturer prefixes — covering common devices like Apple hardware, Raspberry Pi boards, Dell machines, VMware and virtualization platforms, and more. It also normalizes whatever format you paste in (with colons, hyphens, or no separators) into a standard colon-separated format.
The full IEEE OUI registry contains tens of thousands of assigned prefixes across every hardware manufacturer worldwide — far more than any curated list can practically cover. Rather than guess at less certain entries, this tool sticks to a smaller set of prefixes it can verify with confidence, and points you to the official IEEE registry for exhaustive coverage when a prefix isn't recognized.
This is useful for identifying unknown devices on your home or office network by their manufacturer, verifying a device's hardware vendor before troubleshooting, network inventory and security auditing, and general curiosity about what's actually behind an unfamiliar MAC address showing up in a router's client list.
How it works
- Enter a MAC address. Any format — colons, hyphens, or no separators all work.
- The OUI is extracted automatically. The first three octets, which identify the manufacturer.
- See the matched vendor. If the prefix is in our curated list, the manufacturer name is shown.
Examples
Identifying a Raspberry Pi on the network
Input
B8:27:EB:12:34:56
Output
Vendor: Raspberry Pi Foundation