Random MAC Address Generator - Free Online Tool
Random MAC Address Generator
Generate a Random MAC Address with Optional Bit Flags
Understanding Random MAC Addresses
Test Data
Generate realistic-looking MAC addresses for testing network inventory tools or mock device records.
Privacy (MAC Randomization)
Modern devices randomize their MAC address for Wi-Fi privacy — this tool demonstrates the same bit-flag technique.
Virtual Machines
Assign a locally-administered MAC to a VM or container's virtual network interface to avoid colliding with real hardware.
Cryptographically Random
Uses the Web Crypto API's secure random number generator, not Math.random(), for genuine unpredictability.
The Locally-Administered and Multicast Bits
The first byte of a MAC address encodes two special bits: bit 1 (the second-least-significant bit) marks the address as "locally administered" rather than assigned by a hardware vendor from a registered block, and bit 0 marks it as multicast rather than a unicast (single-device) address. Setting the locally-administered bit is the standard way to generate a MAC that's guaranteed not to collide with any real vendor-assigned hardware address.
Key Takeaways
- Cryptographically Random: Uses crypto.getRandomValues() rather than Math.random() for unpredictable output.
- Optional Bit Flags: Toggle the locally-administered and multicast bits independently.
- Client-Side Only: All generation happens locally in your browser — no data is ever sent to a server.