[{"data":1,"prerenderedAt":199},["ShallowReactive",2],{"page-en-root-tools/mac-address-lookup":3},{"content":4,"isFallback":160,"alternates":198},{"id":5,"title":6,"body":7,"description":158,"extension":159,"heroDark":160,"keywords":161,"locale":162,"meta":163,"navigation":190,"path":191,"seo":192,"sitemap":193,"stem":195,"translationKey":196,"__hash__":197},"content/tools/mac-address-lookup.md","MAC Address Lookup — Vendor and OUI Search",{"type":8,"value":9,"toc":155},"minimark",[10,15,18,26,143,149],[11,12],"essential-hero3-section",{"description":13,"title":14},"Paste a single address or your whole ARP table. Each one is matched against all three IEEE block sizes — MA-L, MA-M and MA-S — so small manufacturers come back by name instead of as 'IEEE Registration Authority'. Nothing you paste leaves your browser.","Free \u003Cspan class=\"kw-swipe-d\">MAC address lookup\u003C/span>",[16,17],"tools-mac-address-lookup",{},[19,20],"essential-call-to-action-section",{":primaryButton":21,"subtitle":22,"title":23,"className":24},"{\"text\":\"Get Free Asset Management\",\"url\":\"/free-asset-tracking\"}","A vendor name tells you what showed up on the network. UNIO24 tells you whose it is, where it lives, and when its warranty ends. Free IT asset management for unlimited users — no expiring trial.","Found the device. Now what?",[25],"cta-tight-bottom",[27,28,29],"essential-content-section",{},[30,31,33,46,49,54,57,69,72,76,83,86,90,93,100,103,107,113,125],"template",{"v-slot:description":32},"",[34,35,36,37,41,42,45],"p",{},"A network interface doesn't invent its address — the first half of it is bought. A manufacturer pays IEEE for a block, and every card they ship gets an address inside that block. So ",[38,39,40],"code",{},"A4:83:E7"," at the front of ",[38,43,44],{},"A4:83:E7:2B:0C:1F"," is registered to Apple, and the six digits after it are Apple's own counter. Match the prefix, read the company. That's the whole mechanism, and it's why a lookup can name the maker of a device you've never seen.",[34,47,48],{},"We build asset-tracking software, so treat the pitch above with the skepticism it deserves. The tool itself has nothing to sell you: it loads a registry file and does string matching in your tab.",[50,51,53],"h3",{"id":52},"why-other-lookups-say-ieee-registration-authority","Why other lookups say \"IEEE Registration Authority\"",[34,55,56],{},"Ask around and you'll hear this reported as a bug. It isn't. IEEE sells three sizes of block, and most tools only load the biggest one.",[34,58,59,60,64,65,68],{},"MA-L is the classic 24-bit OUI — three octets, about 40,000 of them issued, and what everyone means by \"the OUI database\". Fine for Apple, Cisco, Samsung. But a company that needs a few thousand addresses rather than sixteen million buys an MA-M (28-bit) or MA-S (36-bit) block, and those live ",[61,62,63],"em",{},"inside"," an MA-L block that IEEE registers to itself. Look up ",[38,66,67],{},"8C:1F:64:AF:A1:23"," against MA-L alone and you get \"IEEE Registration Authority\", which is technically correct and completely useless. Check the 36-bit prefix first and you get DATA ELECTRONIC DEVICES, INC.",[34,70,71],{},"This tool loads all three — 53,784 records — and always matches the longest block first.",[50,73,75],{"id":74},"the-address-tells-you-who-made-the-chip-not-what-the-box-is","The address tells you who made the chip, not what the box is",[34,77,78,79,82],{},"Worth being blunt about, because it trips up asset audits constantly: a MAC identifies whoever built the network interface. A Dell laptop with an Intel Wi-Fi card reports Intel. A whitebox NAS reports whichever Realtek part is soldered to the board. Hyper-V guests report Microsoft, VMware guests report ",[38,80,81],{},"00:50:56",", and neither says anything about the workload inside.",[34,84,85],{},"For network troubleshooting that's usually enough — you're trying to work out whether the unknown thing on VLAN 30 is a printer or somebody's TV. For an equipment register it isn't, and no lookup will fix that. Serial numbers and asset tags survive a NIC swap; MAC addresses don't.",[50,87,89],{"id":88},"randomized-addresses-and-why-half-your-wi-fi-table-is-now-junk","Randomized addresses, and why half your Wi-Fi table is now junk",[34,91,92],{},"Since iOS 14 and Android 10, phones present a different, made-up MAC to every network they join. These are marked in the address itself: if the second hex digit is 2, 6, A or E, the U/L bit is set and the address is locally administered. No vendor owns it. No lookup can name it, here or anywhere else, and any site that returns a manufacturer for one is guessing.",[34,94,95,96,99],{},"The tool flags them rather than shrugging. Same for multicast and broadcast addresses, which turn up in pasted ",[38,97,98],{},"arp -a"," output and aren't device identifiers at all.",[34,101,102],{},"If you're building a device inventory off Wi-Fi MACs, this is the part that quietly breaks it. Wired ports still behave.",[50,104,106],{"id":105},"pasting-a-real-list","Pasting a real list",[34,108,109,110,112],{},"Bulk mode takes up to 1,000 addresses and doesn't care about column order. Feed it ",[38,111,98],{}," output, a DHCP lease export, a CSV from your switch — anything on the line that isn't the address becomes the label, so the CSV that comes back still says which row was the reception printer. Colons, hyphens, Cisco dotted notation and bare hex all parse, mixed together in the same paste if that's what you have. Duplicates get marked instead of dropped, because merged ARP dumps are full of them and the count matters.",[34,114,115,116,124],{},"Nothing downloads until you type. Then the page pulls only the slice of the registry your addresses need — one file per leading octet, about 6 KB each — rather than the whole 1.7 MB list, and falls back to the full file only when a paste is spread across enough octets that fetching them one by one stops paying off. Every match happens locally either way. If you want the raw list yourself, IEEE publishes it at ",[117,118,123],"a",{"href":119,"rel":120,"target":122},"https://standards-oui.ieee.org/",[121],"noopener","_blank","standards-oui.ieee.org",".",[34,126,127,128,132,133,137,138,142],{},"Working out which subnet those devices sit on instead? The ",[117,129,131],{"href":130},"/tools/subnet-calculator","subnet calculator"," does the mask arithmetic and checks a pasted IP plan for overlaps. Generating labels rather than reading addresses? The ",[117,134,136],{"href":135},"/tools/bulk-barcode-generator","bulk barcode generator"," turns a list or CSV into a printable sheet, and the ",[117,139,141],{"href":140},"/tools/barcode-scanner","barcode scanner"," reads tags back with a camera.",[144,145],"essential-faq-section",{":contactLink":146,":faqs":147,"title":148},"{\"text\":\"Tracking the devices, not just identifying them?\",\"callActionText\":\"Talk to sales\",\"url\":\"/contacts\"}","[{\"title\":\"Results\",\"items\":[{\"question\":\"The lookup returned nothing for a brand-new device. Is it broken?\",\"answer\":\"Probably not. IEEE issues new blocks every week, and this registry is a snapshot — an address assigned after it was built has no entry yet. The other common cause is that the prefix genuinely is unassigned, which happens with counterfeit hardware and with devices whose MAC was cloned from something else.\"},{\"question\":\"Two different devices came back with the same vendor and the same OUI. Should they?\",\"answer\":\"Yes, and that is normal. An MA-L block holds about 16.7 million addresses, so every Apple device on your floor shares a handful of prefixes. The OUI identifies the manufacturer, not the unit. If you need to tell two units apart, use the serial number.\"},{\"question\":\"Can I find the device owner or its location from a MAC address?\",\"answer\":\"No. The address is not registered to a person and carries no geographic data — it only maps to whoever bought the block. Locating a device means asking the network: which switch port or access point is seeing that address right now.\"}]},{\"title\":\"Input\",\"items\":[{\"question\":\"Does it accept EUI-64 identifiers?\",\"answer\":\"Yes. Sixteen hex digits parse as EUI-64, which is what you get from IPv6 interface identifiers and from Zigbee and Thread hardware. The vendor still comes from the first 24 to 36 bits, so the lookup works the same way.\"},{\"question\":\"What happens to the addresses I paste?\",\"answer\":\"They stay in the browser tab. The page downloads the registry file and does the matching locally — there is no request carrying your input, which matters if the list came out of a client network you are not supposed to be exporting.\"},{\"question\":\"Why cap it at 1,000 addresses?\",\"answer\":\"Past that the table costs more to render than the lookup costs to run, and pasting a whole log file by accident stops being recoverable. For a larger sweep, split the file — or run the OUI list against it yourself, since IEEE publishes the raw CSVs.\"}]}]","MAC address lookup — the awkward cases",[19,150],{":primaryButton":151,"subtitle":152,"title":153,":secondaryButton":154},"{\"text\":\"Start for Free\",\"url\":\"https://my.unio24.com/signup?utm_source=unio24-site&utm_medium=referral&utm_campaign=tools&utm_content=tools-mac-address-lookup\"}","Every laptop, printer and access point in one register: owner, location, purchase date, warranty expiry, and a QR tag that opens the record from a phone. Start free with 50 assets.","An unknown device is an unregistered asset","{\"text\":\"Book a Demo\",\"url\":\"/demo\"}",{"title":32,"searchDepth":156,"depth":156,"links":157},2,[],"Free MAC address lookup. Paste one address or a whole ARP table and get the registered vendor for each, matched against all three IEEE block sizes. Runs in your browser.","md",false,"mac address lookup, mac address vendor lookup, oui lookup, mac vendor lookup, mac address manufacturer lookup, bulk mac address lookup, find device by mac address, mac address search","en",{"schemaOrg":164},[165,176],{"@type":166,"name":167,"applicationCategory":168,"operatingSystem":169,"description":170,"url":171,"offers":172},"WebApplication","UNIO24 MAC Address Lookup","BusinessApplication","Any","Free browser-based MAC address lookup that resolves one address or a pasted list against the IEEE MA-L, MA-M and MA-S registries, flags randomized and locally administered addresses, and exports results as CSV.","https://unio24.com/tools/mac-address-lookup",{"@type":173,"price":174,"priceCurrency":175},"Offer","0","USD",{"@type":177,"itemListElement":178},"BreadcrumbList",[179,184,187],{"@type":180,"position":181,"name":182,"item":183},"ListItem",1,"Home","https://unio24.com/",{"@type":180,"position":156,"name":185,"item":186},"Tools","https://unio24.com/tools",{"@type":180,"position":188,"name":189,"item":171},3,"MAC Address Lookup",true,"/tools/mac-address-lookup",{"title":6,"description":158},{"loc":191,"lastmod":194},"2026-09-03T01:44:32+03:00","tools/mac-address-lookup",null,"DRzyNb0jpRyDgrxsOGTPFlfiRNZhDhEB-ctGh1PobR8",[],1788397932167]