Developer / Network
Random MAC Address Generator (and Checker)
Generate random MAC addresses for testing and virtual machines, as locally administered unicast addresses or with a vendor prefix, in colon, hyphen, dot, or plain format, and check what kind of address any MAC is.
Random MAC Address Generator (and Checker): Six random bytes are taken from the browser's cryptographic generator. The lowest bit of the first byte is cleared, making the address unicast, and the next bit is set for a locally administered address, which cannot collide with any manufacturer-assigned one. The checker reads the same two bits to tell unicast from multicast and local from universal addresses. Runs 100% locally in your browser with zero server file uploads.
- Category
- Developer tools
- Runs
- In your browser
- Cost
- Free · no sign-up
- Availability
- Ready to use
Runs entirely in your browser
Addresses are made from your browser's cryptographic random numbers. Locally administered addresses, with the second-lowest bit of the first byte set, can never clash with a real device's built-in address, which is why phones use them for Wi-Fi privacy and why they suit tests and virtual machines. Using a manufacturer's prefix makes the address look like that maker's hardware.
The two flag bits
In the first byte, bit 0 is the individual/group bit, 0 for one device and 1 for multicast, and bit 1 is the universal/local bit. That is why locally administered unicast addresses always have 2, 6, A, or E as the second hex digit, such as 02:… or 0A:….
Vendor prefixes
The first three bytes of a universal address are the maker's Organizationally Unique Identifier from the IEEE registry. For IP addressing on the same network, see the IP address converter.
How to use it
- Choose how many addresses and the format.
- Keep locally administered on, or enter a vendor prefix.
- Generate and copy, or paste an address to check it.
Privacy & limitations
Generated in your browser.
Related tools
Frequently asked questions
Why locally administered?
Real network cards carry universally administered addresses from their maker's range. Locally administered ones are reserved for software, so they never clash with real hardware.
Which format should I use?
Colons are standard on Linux and macOS, hyphens on Windows, and dotted groups of four on Cisco equipment; all mean the same address.
Why does my phone show a different MAC on each Wi-Fi network?
Phones use random, locally administered addresses per network for privacy, so networks cannot track the device.
Free tool · runs in your browser · no account required