MAC Address Lookup
Look up the manufacturer behind a MAC address from its OUI prefix, and identify locally administered and randomised addresses.
Last reviewed by the Radiatus Cloud team
MAC Address Lookup
Identify the manufacturer (vendor) of a network device.
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What a MAC address encodes
A MAC address is 48 bits, usually written as six hex pairs. The first three bytes are the Organisationally Unique Identifier, assigned by the IEEE to a manufacturer; the last three are assigned by that manufacturer to the individual interface. Looking up the OUI therefore tells you who made the network chipset, which is not always the same company as the one whose logo is on the device.
Two bits in the first byte matter
The least significant bit of the first byte is the unicast/multicast flag: 0 for a normal address, 1 for multicast. The next bit is the universal/local flag. When it is set, the address is locally administered, meaning it was not assigned by the IEEE and no OUI lookup will be meaningful. Virtual machines, containers, bonded interfaces and privacy-randomised addresses all use locally administered addresses.
MAC randomisation
If a lookup returns nothing for a phone, randomisation is the likely reason. iOS since version 14 and Android since 10 use a different randomised MAC per network by default, specifically to stop venues tracking devices across visits. Windows and modern Linux offer the same. This has real consequences: MAC-based access control lists and captive portal allowlists break, and Wi-Fi analytics that count unique MACs now overcount badly.
MAC addresses do not cross routers
A MAC address is a layer 2 identifier and is only meaningful on the local network segment. Every time a packet passes through a router the source and destination MAC are rewritten for the next hop. You cannot learn the MAC address of a remote internet host, and any service claiming to provide one is not doing what it says.
Not a security control
MAC addresses can be changed in software on essentially every operating system in one command, and they are broadcast unencrypted in Wi-Fi frames, so anyone nearby can observe a permitted address and clone it. MAC filtering deters casual connection attempts and nothing more. Use WPA3, or WPA2 with a strong passphrase, and 802.1X where the environment justifies it.
Related tools
- Port Scanner — Check which common ports respond on a host and understand what each exposed service means. Scan only systems you are authorised to test.
- DNS Misconfiguration — Analyze DNS records (TXT, SPF) for security gaps.
- TLS Compat Tester — Check client-server compatibility for TLS versions.
- Firewall Rule Risk — Evaluate firewall rules for over-permissive exposure.
Frequently Asked Questions
Why does my lookup return no vendor?
Usually because the address is locally administered, indicated by the second-least-significant bit of the first byte being set. Virtual machines, containers and privacy-randomised phone addresses all use these, and they have no IEEE-assigned owner.
Can I find the MAC address of a remote website?
No. MAC addresses are layer 2 identifiers valid only on the local network segment, and routers rewrite them at every hop. Any service claiming to return a remote host's MAC address is not doing what it claims.
Why do phones show a different MAC on each network?
Deliberate privacy randomisation, default on iOS 14 and later and Android 10 and later, to prevent venues tracking a device across visits. It breaks MAC-based allowlists and inflates unique-device counts in Wi-Fi analytics.
Is MAC address filtering good security?
No. Addresses can be changed in software with a single command and are broadcast unencrypted in Wi-Fi frames, so a nearby attacker can observe and clone a permitted one. It deters casual attempts only. Rely on WPA3 or WPA2 with a strong passphrase.
Does the OUI tell me the device brand?
It tells you who was assigned that prefix, which is the maker of the network chipset. That is often a component supplier rather than the brand on the case, so a laptop may report its wireless module vendor instead of the laptop manufacturer.
Privacy & Security
Lookup performed locally in browser.
About This Tool
This tool runs entirely in your browser. No data is sent to any server, ensuring complete privacy. Simply use the interface above to get started — no registration or login required.
Disclaimer: This tool is provided "as is" without warranty of any kind. Results are for educational and utility purposes.
Related Tools
Port Scanner
NetworkCheck which common ports respond on a host and understand what each exposed service means. Scan only systems you are authorised to test.
DNS Misconfiguration
NetworkAnalyze DNS records (TXT, SPF) for security gaps.
TLS Compat Tester
NetworkCheck client-server compatibility for TLS versions.