MAC Address / OUI Lookup
Identify the vendor of any MAC address using the complete IEEE OUI registry — all 39,000+ prefixes bundled client-side. No API calls, no rate limits, works offline after first load.
How to Use
- Paste a MAC address (44:38:39:AB:CD:EF, 44-38-39-AB-CD-EF, 443839ABCDEF — all work).
- The vendor name appears instantly; no network call needed.
- Also detects locally-administered ("random"/"private") MACs used by Apple / Android privacy features.
Paste any MAC above and hit Look up — vendor + block info lands here instantly, fully offline.
Details detected
About the MAC Address / OUI Lookup
Working on networking and IP tasks? The MAC Address / OUI Lookup is a free browser tool that gives you the answer in seconds. Identify the vendor of any MAC address using the complete IEEE OUI registry — all 39,000+ prefixes bundled client-side. No API calls, no rate limits, works offline after first load.
How it works
Enter what you have and read the result as it updates live. It all runs on your own device, so it is quick and private, with nothing to install.
Want the deeper story? The Knowledge Base explains the ideas behind the tools in more detail.
Frequently Asked Questions
How accurate is this?
It uses the complete IEEE MA-L (Organisational Unique Identifier) registry — the authoritative source. Vendors can change the registry; the data is re-pulled any time tools/_dev/build-oui-db.py is re-run.
What is a random MAC?
Devices assign themselves a "locally-administered" MAC to avoid being tracked across Wi-Fi networks. The second-lowest bit of the first byte is 1 in those MACs — the tool flags them.
Is this really offline?
First load fetches the 1.3 MB OUI JSON once. After that it's cached by the browser and works without a network call. No external service involved.
How do I use the MAC Address / OUI Lookup?
Simply type your numbers and read the result, which refreshes the instant you change something. There is nothing to submit and nothing to wait for.
Do I need to install or sign up for anything?
Not at all — it runs in the browser with nothing to install and no account. After it loads once, it even works without an internet connection.
Is my information private?
Yes. Everything happens in your browser. Nothing you type is sent to a server or saved anywhere.
Common Use Cases
Identify a device
Saw an unknown MAC on your network? Find out who made the device.
Inventory audit
Cross-check MACs from ARP / DHCP dumps against the vendor list.
Spot spoofing
A random-looking MAC that doesn't match any known vendor is often spoofed.
Last updated: