MAC Address Vendor Lookup
Enter a MAC address to instantly identify the device manufacturer, its registered address, country, and OUI block.
Updated
Data provided by macaddress.io
How to use MAC Address Vendor Lookup
The MAC Address Vendor Lookup tool identifies the manufacturer behind any network device from its MAC address. The first half of every MAC — the Organizationally Unique Identifier (OUI) — is assigned by the IEEE to a specific company, so entering an address such as 44:38:39:FF:EF:57 reveals the vendor, their registered address, country, and the size of the address block they own. Use it to inventory unknown devices on a network, confirm hardware from a packet capture, or spot spoofed and randomized addresses. The lookup runs on our server against an up-to-date OUI registry, so you get an authoritative answer without installing anything.
- Type or paste the MAC address you want to identify (for example 44:38:39:FF:EF:57).
- Any separator works — colons, hyphens, dots, or none — and the OUI prefix alone is fine.
- Click Look up vendor to query the IEEE OUI registry on our server.
- Read the manufacturer, registered address, country, and OUI block in the result panel.
- If no vendor is shown, the address is likely randomized or locally administered.
Your query is sent to macaddress.ioto fetch results. We don't store it.
How a MAC address is structured
A 48-bit MAC address is written as six hexadecimal octets. The first three octets form the OUI, which the IEEE Registration Authority assigns to a manufacturer; the last three are chosen by that manufacturer to make each device unique. Two bits in the first octet carry meaning: the least-significant bit of the first octet marks a multicast address, and the second-least-significant bit marks a locally administered address. When that local bit is set, the address is not tied to any registered vendor — which is exactly what modern privacy randomization relies on.
| Portion | Bytes | Meaning |
|---|---|---|
| OUI | First 3 (e.g. 44:38:39) | Vendor prefix registered with the IEEE |
| NIC / device | Last 3 (e.g. FF:EF:57) | Unique per-device value set by the vendor |
| U/L bit | Bit 1 of byte 1 | Set = locally administered (no vendor) |
| I/G bit | Bit 0 of byte 1 | Set = multicast, clear = unicast |
Why some MAC addresses have no vendor
Since iOS 14, Android 10, and Windows 10, devices use a randomized, locally administered MAC address when scanning for and joining Wi-Fi networks. These addresses set the U/L bit and are generated on the device, so they are deliberately not present in the IEEE registry. A "no vendor found" or "private" result is therefore a correct and meaningful answer: it tells you the device is using MAC randomization for privacy rather than exposing its real burned-in hardware address. To see the true vendor you would need the device’s actual hardware MAC, which is only visible locally.
Glossary
- MAC address
- A 48-bit hardware identifier assigned to a network interface, written as six hexadecimal octets.
- OUI
- Organizationally Unique Identifier — the first 24 bits of a MAC, registered by the IEEE to a manufacturer.
- IEEE Registration Authority
- The body that assigns OUI blocks to organizations that make networking hardware.
- Locally administered address
- A MAC with the U/L bit set, chosen by software rather than assigned by a vendor — used for randomization.
- EUI-64
- A 64-bit extended identifier that embeds a 24-bit OUI, used in IPv6 interface IDs and some hardware.
Related reading
Frequently Asked Questions
Get weekly tool tips & updates
New tools, power-user tips, and productivity hacks — delivered free every Friday.
No spam, ever. Unsubscribe with one click.
Why use MAC Address Vendor Lookup?
- Identify the manufacturer of any wired or wireless device from its MAC address
- Accept colon, hyphen, dot, or unseparated MAC formats without reformatting first
- Spot randomized or locally administered addresses that belong to no vendor
- Cross-reference unknown devices found in a DHCP table or packet capture
Common use cases
- Inventory an unfamiliar device that appeared on your office Wi-Fi network
- Confirm the hardware vendor of a NIC seen in a Wireshark packet capture
- Investigate whether a connected device is using a spoofed MAC address
- Map MAC prefixes to vendors when auditing a fleet of IoT devices
- Teach how OUI assignment works using a real, looked-up example
Related Network & DNS
MAC Address Generator
Generate random MAC addresses in any format, with optional vendor (OUI) prefixes. Bulk generation supported. Free and private.
WHOIS Lookup
Look up WHOIS registration data for any domain. Find the registrar, creation date, expiry, and nameservers instantly — free, fast, and accurate.
DNS Lookup Tool
Look up DNS records for any domain — A, AAAA, MX, NS, TXT, CNAME, SOA, and CAA records. Free, instant results pulled from authoritative nameservers.
DNS Propagation Checker
Check if your DNS changes have propagated worldwide. Test A, MX, and NS records across 8 global DNS servers to confirm updates are live everywhere.
What Is My IP Address?
Instantly find your public IP address. Shows your IPv4 address as seen by websites and servers, plus quick details about your connection.
HTTP Headers Checker
View HTTP response headers for any URL. Check status codes, security headers, caching, redirects, and server details instantly. Free and private.
Explore all Network & DNS.