MAC address vendor lookup
Paste a MAC address and get the manufacturer behind it, straight from the official IEEE registries. The lookup runs entirely in your browser: the address you type never leaves this page.
Try: — data: IEEE MA-L/MA-M/MA-S registries, 53,000+ assignments.
How to read a MAC address
Every network interface carries a MAC address: six bytes, usually written as twelve hex digits (a4:cf:12:9b:00:01). The address splits in the middle. The first three bytes are the OUI (organizationally unique identifier), a block the IEEE sells to manufacturers; A4:CF:12 belongs to Espressif, the chipmaker inside most smart plugs and DIY boards. The last three bytes are a serial number from that manufacturer's pool. Smaller vendors buy smaller blocks (MA-M, MA-S), where the assigned prefix is 28 or 36 bits long — this lookup checks all three registries, longest prefix first.
So a vendor lookup answers one question well: who made the network chip. That is often enough to tell a Shelly from an iPhone, and it is the first step whenever an unknown device shows up in your network.
When the lookup finds nothing: randomised addresses
The most common reason a lookup comes back empty is not a gap in the registry. Modern phones, tablets and laptops invent a random MAC address per Wi-Fi network by default (iOS calls it Private Wi-Fi Address, Android and Windows call it random hardware addresses). These addresses set the locally administered bit, which this tool flags for you, and they appear in no registry by design.
In practice: an unknown MAC with no vendor in your router list is far more likely someone's phone hiding behind a private address than an intruder. The flip side is that the same phone can appear as several different "devices" over time, which is why counting devices by MAC has become unreliable.
Where to find a device's MAC address
- Router: the client list shows the MAC next to each device — this is the fastest way to look up something that worries you.
- iPhone/iPad: Settings → Wi-Fi → tap the network's ⓘ; the Wi-Fi Address shown is the (usually randomised) address in use.
- Android: Settings → About phone → Status, or per network under Wi-Fi details.
- Windows:
ipconfig /allshows the Physical Address per adapter. - macOS/Linux:
ifconfigorip link; on macOS also System Settings → Network → Details. - Anything else on your network: a network scanner lists every device with its MAC in one sweep, with no menu digging per device.
From vendor name to actual device
The vendor is a hint, and it stops short of the real question: what is this thing, and should it be here? "Espressif" covers thousands of products; "Hui Zhou Gaoshengda" appears in no shop but sits inside half the cheap smart-home gear on the market. Answering the real question takes more signals: hostname, mDNS and UPnP announcements, open ports, HTTP banners.
That is the part DeviceShelf automates. One scan lists every device on your network with vendor, name, open ports and an actual identification, and it keeps watching for new arrivals afterwards. The lookup on this page uses the same IEEE data the app ships with.
Try DeviceShelf free for 7 days What a network scanner does
Questions people actually ask
What does a MAC address tell me?
The first half names the manufacturer of the network chip, assigned by the IEEE. The second half is a serial number from that manufacturer's pool and carries no public meaning.
Why does my lookup return no vendor?
Usually because the address is a randomised private address (locally administered), which appears in no registry by design. A brand-new assignment or a typo are the other common reasons.
Can I find the exact device or its owner from a MAC address?
No. The registry names the chip manufacturer, nothing more — no serial numbers, no locations, no owners. To work out what a device actually is, look at its hostname, services and open ports on your own network.
Is this lookup private?
Yes. The page downloads the registry once and answers every lookup in your browser. The address you type is not sent anywhere.
Are MAC addresses unique?
Hardware addresses are meant to be, but randomised addresses are invented locally and only need to be unique on your network. Duplicates across networks are normal and harmless.