Create valid fake or dummy MAC address text for QA, VMs, containers, labs, simulations, and documentation. Local unicast is the safe default; bulk, vendor-prefix, range, format, and export options run entirely in your browser.
Your generated MAC address
Result
Generating…
Preparing a local unicast address…
Use responsibly: Generated values can collide with another host. Vendor-looking output is not manufacturer-issued. Prefer local unicast for disposable data, use only on systems you own or administer, and follow platform and network policies.
Advanced options, bulk generation, and exports
Every address is unique within the generated batch only—not across devices, files, or sessions.
Fixed prefixes are preserved exactly; their first octet controls the unicast/multicast and local/universal flags.
Vendor mode preserves the registered prefix and requires Unicast + Universal (UAA). The generated suffix is test data, not an address issued by the named organization.
Accepted: 12:34:56, 12-34-56, or 123456. Normalized preview: —
A custom prefix is never altered. Its first octet determines the address type and administration choices shown above.
Enter two complete 12-digit MAC values. If flags are constrained, the range must stay within one first octet and agree with those choices.
Export settings
Generated batch
0 generated
Your generated addresses will appear here.
The output is bounded for easier mobile use.
How to generate a MAC address
Use the default Local + Unicast result for ordinary test data, or open advanced options.
Choose the type, administration bit, format, case, quantity, and optional prefix or range.
Select Generate batch, verify the annotations, then copy or export TXT, CSV, or JSON.
This page only generates text values. It does not detect or change your device's real MAC address.
Worked examples
Local + Unicast + Colon 02:1A:73:C4:9B:20 The first octet has I/G=0 and U/L=1.
Cisco dotted notation 001A.2B3C.4D5E Three groups of four hexadecimal digits.
Practical uses
QA fixtures Populate repeatable-looking network records without copying production identifiers.
VMs and containers Create local unicast candidates for owned lab workloads, subject to platform policy.
Network simulations Build unique-in-batch node lists or range-constrained datasets.
DHCP demonstrations Create fictional client identifiers for screenshots, training, and examples.
Documentation Use clearly labeled dummy values rather than exposing a real adapter address.
MAC address technical reference
An EUI-48 value contains six octets (48 bits). In a universally administered address based on an IEEE MA-L assignment, the first three octets are the OUI and the assignment owner supplies the last three. Locally administered values are created under local policy instead.
Octet 1 flags
Octet 2
Octet 3
Octet 4
Octet 5
Octet 6
First 24 bits: IEEE OUI/MA-L or local prefix | Last 24 bits: organization-assigned identifier or random suffix
First-octet bit example
02 is binary 00000010. Reading the two rightmost bits, I/G is 0 (unicast) and U/L is 1 (local). The generator changes these bits only when no fixed prefix controls them.
Common formats
Format
Example
Common use
Colon
AA:BB:CC:DD:EE:FF
Linux, macOS, logs, and general documentation
Hyphen
AA-BB-CC-DD-EE-FF
Windows interfaces and inventory exports
Cisco dotted
AABB.CCDD.EEFF
Cisco command-line interfaces
Plain
AABBCCDDEEFF
Databases, APIs, and compact identifiers
Random space and collisions
With both the local and unicast bits fixed, 46 bits remain random: 246 possible values. A fixed 24-bit prefix leaves a 24-bit suffix: 224 possible values. Collision probability rises as a batch grows, particularly with a fixed prefix, so the generator uses strong browser randomness plus a Set and retries until every value in the current batch is distinct. That guarantee ends when the batch is replaced or exported.
Technical notes and limitations
Reviewed and updated: 17 July 2026
The IEEE Registration Authority assigns identifier blocks. Reusing a listed prefix here does not grant rights to that allocation or make the random suffix organization-issued.
The generator uses crypto.getRandomValues(), not Math.random(). Browser randomness and in-batch duplicate rejection improve generation quality but cannot coordinate with other devices or sessions.
Universal (UAA) describes the U/L bit state. Only an assignment owner following its allocation process can claim universal uniqueness; clearing the bit on random data is insufficient.
Privacy-address features vary by platform and managed-network policy. Generated text is not a substitute for your operating system's supported configuration controls.
What is the difference between a locally and universally administered MAC address?
A locally administered address has the U/L bit set and is created by software or a network administrator. A universally administered address has that bit clear and is normally issued from an IEEE-assigned block by its owner. Clearing the bit on a random value does not make that value globally unique.
What happens when I choose a vendor OUI?
The selected 24-bit IEEE MA-L prefix is preserved and the address is generated as universal unicast. The vendor-looking result is test data; it was not issued by that manufacturer and must not be represented as one of its assigned device addresses.
Are the generated MAC addresses valid and unique?
Each result is a syntactically valid 48-bit value, and this tool prevents duplicates within the current generated batch. It cannot guarantee uniqueness across other devices, browser sessions, saved files, or networks.
Why does the first byte change with some settings?
The two lowest-order bits of the first octet encode individual/group and universal/local status. Without a fixed prefix, the generator sets or clears those bits to match your choices. Vendor and custom prefixes are preserved instead of being silently rewritten.
What is Cisco dotted notation?
Cisco dotted notation writes the 12 hexadecimal digits as three groups of four, for example 001A.2B3C.4D5E. It represents the same six-octet value as 00:1A:2B:3C:4D:5E.
Can I use these addresses for virtual machines or test data?
Local unicast addresses are the preferred default for disposable fixtures, owned lab systems, virtual machines, containers, simulations, and documentation. Check platform and network policies, and confirm that an address is unused before assigning it on a real network.
Does this tool change my device's real MAC address?
No. This page only generates text in your browser. It does not inspect, configure, or change any network adapter.
Why can vendor lookup fail for a randomized address?
Locally administered and privacy-randomized addresses are not manufacturer assignments, so their first 24 bits may not identify a vendor. Even vendor-looking test output only reuses a prefix and does not prove who made a device.
