MAC Address Generator
Generate random, valid MAC addresses in your browser - locally administered or unicast, in colon, dash or Cisco dot notation - using a cryptographic random source.
Random MAC address generator
Addresses are produced with a cryptographic random source, right here in your browser.
Locally administered addresses (second hex digit 2, 6, A or E) are reserved for private assignment and cannot collide with vendor-assigned hardware addresses - the safe choice for labs, VMs and testing.
About MAC Address Generator
This generator produces syntactically valid 48-bit MAC addresses on demand, from a single address up to a hundred at once. Every address is drawn from the browser's cryptographic random number generator (crypto.getRandomValues), so the values are unpredictable rather than sequential or pattern-based. Nothing is generated on a server: the addresses are created locally in your browser and never uploaded.
By default the locally-administered bit is set, marking each address as assigned by software rather than by a hardware vendor. This is the safe choice for testing because the locally-administered range is reserved for private use and cannot collide with any manufacturer-issued MAC. Turn the option off if you instead want a universal-style unicast address. In all cases the multicast bit is cleared, so every result is a unicast address - the correct type for identifying an individual interface.
Output is available in the three notations you'll actually encounter: colon-separated (aa:bb:cc:dd:ee:ff), hyphen-separated (aa-bb-cc-dd-ee-ff) and Cisco-style dotted (aabb.ccdd.eeff), each in lower or upper case. A copy button grabs the whole batch at once, ready to paste into a config file, VM manager or test fixture.
Because it runs client-side, the generator is fully private and works without a network round-trip - useful when you need throwaway addresses quickly, in bulk, or in an offline environment.
How to use it
- 1Choose how many addresses to generate, from 1 to 100.
- 2Pick a format - colons, dashes or Cisco dotted - and toggle uppercase if you need it.
- 3Leave locally administered on for safe test addresses, or switch it off for a universal-style unicast address.
- 4Click Generate, then use the copy button to grab the whole list.
Common use cases
- -Assign non-conflicting MAC addresses to virtual machines, containers or lab devices.
- -Create realistic test data for network software, DHCP servers or firewall rules.
- -Produce placeholder MACs for documentation, diagrams and examples.
- -Generate locally administered addresses guaranteed not to clash with real hardware.
Frequently asked questions
- What is a locally administered MAC address?
- A locally administered address is one assigned by software rather than burned into hardware by a manufacturer. Its locally-administered bit is set (the second hex digit is 2, 6, A or E), which reserves it for private use and guarantees it will not collide with any vendor-issued address.
- Are the generated MAC addresses random and safe to use?
- Yes. Each address is produced with the browser's cryptographic random generator (crypto.getRandomValues), and by default the locally-administered bit is set, so the results are valid unicast addresses safe for virtual machines, labs and testing.
- What MAC address formats can this tool generate?
- Three common notations: colon-separated (aa:bb:cc:dd:ee:ff), hyphen-separated (aa-bb-cc-dd-ee-ff) and Cisco-style dotted (aabb.ccdd.eeff), each available in lower or upper case.
- Will a generated MAC address clash with real hardware?
- Not when the locally-administered option is on. Vendor hardware uses universally-administered addresses, while the locally-administered range is reserved for private assignment, so there is no overlap with manufacturer-issued MACs.
- What is the difference between a unicast and a multicast MAC address?
- The least-significant bit of the first byte marks an address as multicast when set and unicast when clear. This generator always clears that bit, so every address it produces is unicast - the correct type for identifying a single interface.
- Is anything sent to a server when I generate addresses?
- No. Generation happens entirely in your browser with client-side JavaScript. No address is transmitted or stored, which keeps the tool fully private.