MAC Address Generator
Generate random MAC addresses in bulk with custom formats, address types and prefixes.
Free Random MAC Address Generator: What It Does
A MAC address generator creates random 48-bit hardware addresses, written as six pairs of hexadecimal digits. This free random MAC address generator makes up to 100 addresses at a time in your browser, in colon, hyphen, dotted or plain format, with control over unicast, multicast, locally administered and universally administered types.
You choose how many addresses you want, how they should look, what type they should be, and optionally which prefix they should start with. The results appear as a simple list that you can copy, download or regenerate with one click. It is made for testing, learning and development, such as filling a lab setup, a database or a piece of documentation with realistic placeholder addresses.
It is worth knowing what the tool does not do. It does not look up manufacturers, and it does not read or change the MAC address of your own device. It only generates text.
How to Generate a Random MAC Address
- Set the quantity. Enter how many addresses you want in the Number of MAC Addresses box. Any value from 1 to 100 works, and the default is 10.
- Choose the letter case. Select Uppercase (A to F) or Lowercase (a to f) depending on how your project writes hexadecimal values.
- Pick a format. Choose between colon, hyphen, dotted or no separator. The menu shows an example pattern for each one.
- Select an address type. Choose Random, Unicast, Multicast, Locally Administered or Universally Administered. A one line hint under the menu tells you which bit is set.
- Add a prefix if you need one. Type the first octets in the Optional Prefix field, or leave it empty for fully random addresses. An error message appears if the prefix is not valid.
- Generate and use the results. Click Generate MAC Addresses, then copy any single address, use Copy All, download the list, regenerate a new set, or clear the results.
MAC Address Generator Features and Options
Bulk Generation
Create anywhere from 1 to 100 MAC addresses in a single run. The quantity box defaults to 10 and shows an error message if the number is outside that range.
Four Output Formats
Choose colon, hyphen, dotted (three groups of four), or no separator at all, and pick uppercase or lowercase letters for the final generated result to match your preference.
Five Address Types
Pick random, unicast, multicast, locally administered or universally administered. A short hint under the menu explains which bit each option sets.
Optional Custom Prefix
Lock the first one to five octets of every generated address by typing a prefix such as 00:1A:2B or 001A2B. Leave it blank for a fully random address with no fixed prefix.
Copy, Download and Regenerate
Copy a single address, copy the whole list, download it as mac-addresses.txt, regenerate with the same settings, or clear the results.
Browser-Based, No Sign-Up
Addresses are generated by JavaScript running on the page itself. There is no account, and your settings and results are not sent anywhere.
What Is a MAC Address? Structure and Valid Characters
A MAC address (Media Access Control address) is a 48-bit identifier used to recognise a network interface on a local network. It is written as six pairs of hexadecimal digits, and each pair is called an octet. On real hardware, the first three octets usually identify the manufacturer (the OUI) and the last three are a number chosen for that specific device.
The first octet also carries two small flags that matter when you generate test addresses. One says whether the address is unicast or multicast, and the other says whether it is universally or locally administered. The generator lets you set those flags directly with the Address Type menu.
| Part of the Address | Size | What It Usually Means |
|---|---|---|
| First three octets | 24 bits | Manufacturer prefix (OUI) on real hardware, and the place where the two flag bits live |
| Last three octets | 24 bits | Device specific number, which this tool fills in randomly |
| Whole address | 48 bits | Six octets, which is 12 hexadecimal digits, shown in one of four formats |
| Valid characters | 16 symbols | Digits 0 to 9 and letters A to F. Upper or lower case gives the same value |
Unicast, Multicast, Local and Universal MAC Addresses Explained
Each type option in this tool works by adjusting one bit of the first octet after the address is built. Nothing else about the address is changed.
Unicast or Multicast
The last bit of the first octet decides whether an address points to one interface or to a group. Choosing Unicast forces that bit to 0, and Multicast forces it to 1.
Universal or Local
The second-to-last bit of the first octet indicates who assigned the address and determines how the MAC address is managed. Universally Administered sets it to 0, while Locally Administered sets it to 1 for custom configuration.
| Address Type | What the Tool Does | Typical Use |
|---|---|---|
| Random | Leaves every bit random | Quick placeholder data |
| Unicast | Sets the last bit of the first octet to 0 | Addresses meant for one interface |
| Multicast | Sets the last bit of the first octet to 1 | Testing group addressing or parsing logic |
| Locally Administered | Sets the second to last bit to 1 | Virtual machines, containers and lab devices |
| Universally Administered | Sets the second to last bit to 0 | Addresses that look manufacturer assigned |
Each type sets only its own bit. The Random option can produce multicast addresses roughly half of the time, and the Locally Administered option leaves the unicast or multicast bit to chance. If you need both bits fixed, use the prefix trick described below.
How to Generate a MAC Address with a Custom Prefix (OUI)
The Optional Prefix field accepts one to five octets. Type them with colons, hyphens or no separators at all, and anything that is not a hexadecimal digit is ignored. The prefix must contain an even number of hex digits, so each octet needs both characters. The remaining octets are then filled in randomly for every address.
Because the address type is applied after your prefix is placed, it can change the first octet you typed. The table below shows what happens with the prefix 00:1A:2B and a few other combinations.
| Prefix Entered | Address Type | Addresses Start With |
|---|---|---|
| 00:1A:2B | Random | 00:1A:2B |
| 00:1A:2B | Locally Administered | 02:1A:2B |
| 00:1A:2B | Multicast | 01:1A:2B |
| 02 | Unicast | 02 |
The last row is the simplest way to get a locally administered unicast address. A first octet of 02 has the unicast bit at 0 and the local bit at 1, so every result is suitable for a virtual adapter or a lab device.
MAC Address Formats: Colon, Hyphen, Dotted and Plain
A valid MAC address always has 12 hexadecimal digits, so 00:1A:2B:3C:4D:5E and 001A.2B3C.4D5E are the same address written two ways. All four formats describe the same 48-bit value. The right one depends on where you plan to use the address, so match the style of the system or file you are working with.
| Format | Example | Where You Often See It |
|---|---|---|
| Colon | 00:1A:2B:3C:4D:5E | Linux and macOS tools, many network utilities |
| Hyphen | 00-1A-2B-3C-4D-5E | Windows network commands such as ipconfig /all |
| Dotted | 001A.2B3C.4D5E | Cisco style device configuration |
| No separator | 001A2B3C4D5E | Databases, spreadsheets and plain text fields |
Common Uses for a Random MAC Address
Network Labs and Simulations
Fill a lab topology, a switch table or a packet capture exercise with believable addresses for realistic networking practice without touching any real hardware or live production networks.
Virtual Machines and Containers
Virtual network adapters need a MAC address of their own. A locally administered address keeps the test machine clearly separate from manufacturer assigned ones.
Test Data for Software
Use bulk output to check input validation, sorting, database columns and import scripts with every supported format. For other kinds of test identifiers, the Token Generator can help.
Learning and Documentation
Write tutorials, slides, and support articles with sample addresses instead of showing the real address of an actual device or any connected network hardware.
Are Random MAC Addresses Unique and Safe to Use?
The random part of every address comes from your browser’s built-in cryptographic random number generator, not from a predictable pattern. Within a single run, the tool also skips any address that has already appeared, so a batch never contains the same address twice.
Uniqueness inside a batch is not the same as uniqueness in the real world. The addresses are not checked against devices that exist, so one could match a real interface by chance. That is why the tool is intended for testing, learning and development, and why you should be careful before using generated addresses on a live network.
Does a MAC Address Generator Change My Real MAC Address?
No. The generator only displays text that you can copy or download. Changing the address of a real network adapter is done in the operating system or the device settings, and it is not part of this tool. Use the results as sample values for labs, test records and documentation.
Tips for Getting Better MAC Address Results
VM Style Prefix: 02
Type 02 in the prefix box and choose Unicast or Locally Administered. Every address starts with 02, which is both unicast and locally administered.
Sort Your List Afterward
Need the addresses in order? Paste the downloaded list into the Text Sorter to arrange them alphabetically or numerically.
Check the Bits Yourself
Convert the first octet with the Binary Converter to see exactly which flag bits are set in an address.
Validate Formats in Your Code
Building a form or parser? Try a pattern against the output in the Regex Tester for all four formats.
Frequently Asked Questions
How do I generate a random MAC address?
Set how many addresses you need, choose a letter case, a format and an address type, then click Generate MAC Addresses. The list appears below the form and you can copy or download it right away. Pressing Enter in any of the fields works as well.
How many MAC addresses can I generate at once?
Up to 100 per run. The default is 10, and entering a number below 1 or above 100 shows an error until you fix it.
What does a valid MAC address look like?
A MAC address has 12 hexadecimal digits, which means the digits 0 to 9 and the letters A to F. They are usually grouped in pairs, for example 00:1A:2B:3C:4D:5E. Upper or lower case does not change the value.
Which MAC address formats does the generator support?
Four formats: XX:XX:XX:XX:XX:XX with colons, XX-XX-XX-XX-XX-XX with hyphens, XXXX.XXXX.XXXX in the dotted style, and XXXXXXXXXXXX with no separators. Each can be shown in uppercase or lowercase.
What is the difference between unicast and multicast MAC addresses?
A unicast address identifies a single network interface, while a multicast address is meant for a group of interfaces. The difference is the last bit of the first octet: 0 for unicast and 1 for multicast.
How do I generate a MAC address with a specific prefix or OUI?
Type the starting octets in the Optional Prefix field, for example 00:1A:2B or 001A2B. You can enter one to five octets, and the remaining part of each address is filled in randomly. Colons and hyphens are ignored, so either style works.
Can I generate a MAC address for a virtual machine?
Yes. Enter 02 as the prefix, choose Unicast or Locally Administered, and generate. Every result starts with 02, which is a unicast and locally administered address. You can then copy it into the network settings of your virtual machine or lab tool.
Why did my prefix change after I picked an address type?
The address type is applied to the first octet after your prefix is placed. If your first octet has a different value for the bit that type controls, that bit is overwritten. For example, the prefix 00:1A:2B with Multicast produces addresses starting with 01:1A:2B.
How do I get an address that is both unicast and locally administered?
Each type option sets only its own bit, so the other bit stays random. To fix both, enter 02 as the prefix and choose Unicast or Locally Administered. The first octet of every result will then be 02.
Does this tool change the MAC address of my device?
No. It only produces text that you can copy or download. It does not read, replace or apply anything to your computer, phone or router.
Can a generated MAC address match a real device?
Yes, it is possible, because the addresses are random and not checked against any list of devices in use. Duplicate addresses on one network can cause connectivity problems, so treat the results as test and learning data.
Are the addresses in one batch unique?
Yes. If the same address comes up twice within a single run, the duplicate is skipped and another one is generated, so a batch will not contain repeats.
Can I download the generated MAC addresses?
Yes. Click Download to save the current list as a plain text file named mac-addresses.txt, with one address per line. Copy All gives you the same one-per-line list on your clipboard.
Are my settings or results sent to a server?
No. The addresses are created in your browser using its built-in random number generator, and the copy and download features work on your device. Nothing you choose or generate is uploaded.
Does this tool work on mobile devices?
Yes. The layout adapts to smaller screens, with stacked fields and full width buttons, so you can generate, copy and download addresses on a phone or tablet.