Example
Valid EUI-48 (Unicast, Universally administered) — OUI 001A2B
MAC Address Validator
Check whether a MAC address is well-formed and identify its vendor OUI instantly in your browser. Free online MAC address validator.
Enter the values below, then press Calculate (or press Enter). The calculator updates your results instantly. Try different values to see how your inputs change the outcome.
- MAC address — enter a text value. A typical MAC address would be e.g. 00:1A:2B:3C:4D:5E.
- Review your results — the key output is highlighted, with supporting figures below.
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Results
Result
| Detail | Value |
|---|---|
| Type | |
| Vendor OUI | |
| Normalised (hex) |
What is this calculator for?
Validate the format of a MAC address and read its vendor prefix and address class.
How to Use This Calculator
Enter the values below, then press Calculate (or press Enter). The calculator updates your results instantly. Try different values to see how your inputs change the outcome.
- MAC address — enter a text value. A typical MAC address would be e.g. 00:1A:2B:3C:4D:5E.
- Review your results — the key output is highlighted, with supporting figures below.
What You'll Need
- MAC address
- a text value · required
About This Calculator
A MAC address is 48 bits (EUI-48, six groups of two hex digits) or 64 bits (EUI-64, eight groups), typically written colon- or dash-separated.
The first octet encodes unicast vs multicast (lowest bit) and universal vs locally administered (second-lowest bit). The first three groups form the vendor OUI.
Validation runs entirely in your browser.
Worked Examples
Frequently Asked Questions
What is the difference between EUI-48 and EUI-64?
EUI-48 is the classic 6-group MAC; EUI-64 is the 8-group form used in IPv6 and some networking standards. This validator accepts both.
What does the OUI tell me?
The OUI (first 24 bits) identifies the manufacturer that assigned the address range. This tool extracts it; a full name lookup would require a vendor database.