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MAC Format Converter

Convert a MAC address between the four notations, and read the two bits that matter.

What you provide

Any separator, or none. Colons, hyphens, dots or bare hex all work.

Result

00:1a:2b:3c:4d:5e

The same address in the four notations different systems expect. The two bits worth reading are both in the first octet: the lowest bit distinguishes unicast from multicast, and the next one up marks a locally administered address. This one is universally administered, so the first three octets are the vendor identifier.

Diagnostic telemetry
Colon (Unix, IEEE)
00:1a:2b:3c:4d:5e
Hyphen (Windows)
00-1A-2B-3C-4D-5E
Dot (Cisco)
001a.2b3c.4d5e
Bare
001a2b3c4d5e
AdministrationBurned in by the manufacturer, so the first three octets identify the vendor.
Universally administered
CastThe least-significant bit of the first octet.
Unicast

What this cannot tell you

  • Formats and classifies. It does not look up the manufacturer — the OUI lookup tool does that, and only for universally administered addresses.
  • A locally administered address has no manufacturer to look up. Randomised Wi-Fi MACs are the common case and are deliberately meaningless.
  • Runs entirely in your browser. Nothing is looked up, transmitted or stored.

Take this with you

How this calculation works

The address is stripped to its twelve hex digits and rendered in the four notations different systems use: colons for Unix and the IEEE, hyphens for Windows, four-digit dotted groups for Cisco, and bare hex. Two bits in the first octet are then read out, because they change what the address means. The lowest bit distinguishes unicast from multicast. The next one up marks a locally administered address — set by a phone randomising its MAC for Wi-Fi scanning, by a virtual interface, or by a manual override — and when it is set there is no vendor to look up, because no vendor assigned it.

What the results mean

Colon
The Unix and IEEE convention, and the most widely accepted on input.
Hyphen
Windows convention, conventionally uppercase.
Dot
Cisco's four-digit groups.
Locally administered
Assigned locally rather than burned in. No manufacturer, and increasingly the default on phones.

Common problems and fixes

The vendor lookup finds nothing
Check whether the address is locally administered. If that bit is set, no manufacturer assigned it and there is nothing to find.
My phone shows a different MAC on every network
Randomised MAC addressing, on by default on modern iOS and Android. Each randomised address is locally administered.
Which format should I use?
Whichever the system you are pasting into expects. They are the same address, and most tools accept colons.

Frequently asked questions

What does locally administered mean?

That the address was set by software rather than assigned by the manufacturer. The second-least-significant bit of the first octet marks it, and it is how randomised Wi-Fi MACs avoid colliding with real ones.

Why does my phone randomise its MAC?

Because a fixed MAC broadcast while scanning for Wi-Fi lets anyone with a receiver track a device between locations. Randomising per network closes that.

Do the different formats mean anything different?

No. They are the same 48 bits with different punctuation, and which one appears is purely a convention of the vendor whose tool you are using.

Put this on your own site

Free to embed, no attribution required beyond the source link the frame carries itself. It runs entirely in your visitor's browser, sets no cookies and loads no third-party script.

Embed code
<iframe src="https://runthetests.com/embed/mac-address-formatter/" width="100%" height="560" style="border:1px solid #e5e5e5;border-radius:8px" title="MAC Format Converter" loading="lazy"></iframe>

Preview it at https://runthetests.com/embed/mac-address-formatter/. Embedded pages are marked noindex, so yours stays the canonical copy — not this one.

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