MAC Address Generator

📖 Tool Introduction

When you set up virtual machines, containers, network labs or batch-configure network cards, you often need a MAC address that is valid and free of conflicts. A MAC address is 48 bits long: the first 24 bits are the OUI assigned to a vendor, and the last 24 bits are numbered by the device itself. The lowest two bits of the very first octet have a strict meaning: bit0 decides whether the address is unicast (0) or multicast (1), and bit1 decides whether it is a globally unique vendor address (0) or a locally administered random address (1). If you simply fabricate six random bytes, it is surprisingly easy to set those two bits wrong and end up with a semantically invalid address. The MAC Address Generator exists specifically to avoid that: in the random locally-administered mode it forces the low two bits of the first octet to 10, which means unicast and locally administered at the same time, exactly as the RFC requires. Alternatively you may pick a real vendor OUI from the built-in list covering Intel, VMware, VirtualBox, QEMU/KVM and Cisco, and the tool randomises the last three bytes to mimic a genuine network card from those vendors. You can produce between one and fifty addresses per run, choose colon, hyphen or Cisco dotted notation, and toggle the letter case. The UI uses a two-pane layout with the options on the left and the generated list on the right, and every row has its own copy button. Because all randomness is generated inside your browser, nothing is uploaded and no network request is ever made.

✨ Key Features

• Correct bit flags: random local addresses fix the low two bits of the first octet to 10, ensuring unicast (bit0=0) and locally administered (bit1=1) per the RFC
• Common OUI prefixes: built-in first three bytes for Intel, VMware, VirtualBox, QEMU/KVM and Cisco
• Custom OUI: type any six hex digits as the first three bytes and the last three are random
• Batch generation: produce from one to fifty addresses in one run, listed with numbers
• Three formats: colon aa:bb:cc:dd:ee:ff, hyphen, and Cisco dotted aabb.ccdd.eeff, with case toggle
• Per-row copy and batch export: copy a single row, copy all, or download as a text file

📝 How to Use

1. Pick either random locally-administered or a vendor OUI prefix from the dropdown
2. If you choose custom, type the first three bytes such as 00:11:22 into the input that appears
3. Set the count (1-50), the output format and the letter case
4. Click the Generate button and the list on the right fills with all MAC addresses
5. Click a row copy button to take one address, or use Copy all and Download for batch export

⚠️ Notes

• Random nature: locally-generated addresses are meant for experiments and simulations only and are not guaranteed to be conflict-free on a live network
• OUI ownership: the preset OUIs are for format simulation; using a vendor prefix does not make your device that vendor
• Custom OUI format: must be six hex digits, colon, hyphen or no separators are all accepted, otherwise a format warning appears
• Count limit: at most fifty addresses per run to keep the list readable
• Generation only: the tool never writes an address to a network card or system; everything stays in your browser