MAC Address Generator & Lookup

Generate random MACs, reformat any notation & look up the vendor.

Generate random MACs, reformat any notation & look up the vendor. Free and 100% private — runs entirely in your browser, nothing is ever uploaded.

About MAC Address Generator & Lookup

MAC Address Generator & Lookup is a free in-browser tool that generates random, safe-for-testing MAC addresses and decodes any MAC you paste. It creates locally-administered unicast addresses (so they never collide with real hardware) using your browser's secure crypto randomness, and on lookup it normalizes the MAC into every notation, identifies the vendor from the OUI, and decodes the unicast/multicast and universal/local flags. Everything runs 100% in your browser - nothing is uploaded.

How to use MAC Address Generator & Lookup

  1. To make addresses, set the Notation (Colon, Hyphen, Dot/Cisco, or Bare), pick a Count from 1 to 50, optionally turn on Uppercase, then press Generate.
  2. Click Copy all to grab the whole batch, or re-press Generate to re-roll a fresh set of random locally-administered unicast MACs.
  3. To decode a MAC, scroll to Lookup & inspect and paste any address - colon, hyphen, dot, or bare notation, in any case.
  4. Read the normalized address rendered in all four notations and copy any one with its inline copy button.
  5. Check the Vendor (OUI), Cast (Unicast/Multicast), and Administration (Universal/Locally administered) panels to understand the address.
  6. Use the same tool to reformat a MAC: paste it once, then copy whichever notation your switch, router, or config file expects.

Frequently asked questions

Are the generated MAC addresses safe to use for testing?
Yes. Every generated address is a locally-administered unicast MAC: the tool sets the locally-administered bit and clears the multicast bit in the first octet. Locally-administered addresses are reserved for private/local use and are guaranteed not to collide with real, vendor-assigned hardware addresses, so they are ideal for labs, VMs, mock data, and tests.
Why does the vendor lookup say Unknown for my MAC?
The vendor (OUI) lookup uses a curated list of the most common prefixes - Apple, Google, Cisco, Intel, Dell, Samsung, VMware, VirtualBox, QEMU/KVM, Hyper-V, Raspberry Pi and more - rather than the full IEEE registry, which is roughly 35,000 entries and around 1 MB. Bundling the whole registry would bloat the page, so less-common prefixes show as Unknown even though the MAC itself is parsed and flagged correctly.
What do the Unicast and Universal flags mean?
They come from the two lowest bits of the first octet. Bit 0 is the unicast/multicast bit: 0 means unicast (sent to one interface), 1 means multicast (a group). Bit 1 is the universal/local bit: 0 means a universal OUI-assigned address from the manufacturer, 1 means locally administered (set by software, like a randomized or generated MAC).
Can I convert a MAC between colon, hyphen, dot and bare formats?
Yes. Paste any MAC into Lookup & inspect and the tool instantly shows it in all four notations - colon (aa:bb:cc:dd:ee:ff), hyphen (aa-bb-cc-dd-ee-ff), Cisco dot (aabb.ccdd.eeff), and bare (aabbccddeeff) - each with its own copy button. Input is case-insensitive and accepts any of these notations.
Is my data uploaded anywhere when I look up a MAC?
No. The entire tool runs locally in your browser. Generation uses your browser's Web Crypto API for randomness, and the OUI vendor list ships with the page, so neither the MACs you generate nor the ones you paste ever leave your device - there are no servers, accounts, or network calls involved.