MAC Address Generator
NetworkBulk-generate spec-compliant random MAC addresses with a vendor OUI prefix and colon, hyphen or dot separators, then copy the whole batch in one click.
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About MAC Address Generator
A MAC address is a network card's physical identifier, 48 bits (6 bytes) long: the first 3 bytes are the vendor OUI and the last 3 are vendor-assigned. Everything runs on your device with nothing sent to any server. For example, generate a random MAC like 3C:22:FB:xx:xx:xx with vendor-range or fully random prefixes, useful for testing device address filters.
How to Use
- Open the MAC Address Generator tool
- Enter the address or query parameters
- Adjust the output options as needed
- Click the Query button; results appear in real time
- Copy or export the result
Use Cases
- VM interfaces — Assign non-conflicting MACs in bulk to KVM, VMware, or Docker bridged adapters.
- Re-addressing tests — Generate locally-administered (LAA) addresses to test port security and MAC binding.
- Privacy rotation — Prepare spec-valid random MACs for Wi-Fi randomization to resist long-term tracking.
- Network simulation — Populate unique L2 addresses for many virtual nodes in ns-3, GNS3, and similar tools.
- Firmware placeholders — Use random MACs during embedded development before burning real OUIs at production.
- MAC spoofing scripts — Generate random locally-administered addresses for privacy scripts that rotate the MAC at each boot.
- Test access lists — Produce a range of MACs with specific OUIs to validate port-security and ACL rules on switches.
FAQ
Will generated MACs collide with real devices?
Set bit 2 of the first byte (the locally-administered bit) to 1 to produce an LAA address. These never clash with factory globally-unique (UAA) addresses, making them ideal for testing.
How do I ensure a unicast address?
Set the least-significant bit of the first byte to 0 for unicast; 1 means multicast. This tool defaults to unicast so frames are not treated as broadcast.
Can I fix the first three bytes to a vendor?
Yes, lock a known OUI prefix and randomize the last three bytes. To look up which vendor a MAC belongs to, use our MAC Address Lookup tool.
Which separator formats are supported?
Colon (00:1A:2B), hyphen (00-1A-2B), dotted Cisco style (001A.2B3C), and plain hex with no separator — choose per target system.
Is the randomness reliable?
Bytes come from the browser's cryptographically secure random source, evenly distributed and fit for generating many non-repeating addresses.
Online MAC generator vs desktop software — any difference?
The online version needs no download or install: everything runs locally in your browser with nothing uploaded, so it is as safe as desktop software while working on Windows, macOS, Linux, and mobile alike.
How do I apply a generated MAC to my network adapter?
Windows: Device Manager → adapter Properties → Advanced → Network Address (no separators). Linux: ip link set dev eth0 address NEW. macOS: sudo ifconfig en0 ether NEW. Use a locally-administered (LAA) address to avoid clashing with real hardware.
How do I find which vendor a MAC address belongs to (MAC vendor lookup)?
Use our MAC Address Vendor Lookup tool (/mac-address-lookup.html): paste any MAC to look up the vendor name, country, and registrant from the official IEEE OUI database, with batch support.
What is the locally-administered (U/L) bit and why set it?
Bit 2 of the first byte: 0 means globally unique (factory-assigned), 1 means locally administered (LAA). Random MACs with this bit set live in the LAA space and can never collide with any factory address — Wi-Fi randomization and VM NICs use exactly this class.