MAC Address Lookup

Read the OUI, assignment type and every notation of a MAC.

Free
No signup
Nothing uploaded
No watermark

MAC address

OUI (manufacturer prefix)

00:1A:2B

Assignment

Universal

Type

Unicast

Every notation

Colon separated: 00:1A:2B:3C:4D:5E
Hyphen separated: 00-1A-2B-3C-4D-5E
Cisco (dot): 001a.2b3c.4d5e
No separator: 001A2B3C4D5E
Lowercase: 00:1a:2b:3c:4d:5e

The universally administered bit is set, so the first three bytes are a real manufacturer prefix registered with the IEEE.

How to Read a MAC Address and Its Prefix

A MAC address like 00:1A:2B:3C:4D:5E is printed on routers, listed in your router's connected-devices page and shown in phone Wi-Fi settings. It looks like random hex, but the first half and two hidden bits inside it tell you a lot.

Paste an address in any common format and this tool pulls out the manufacturer prefix, tells you whether the address was set at the factory or made up by software, whether it points at one device or a group, and rewrites it in every notation you are likely to need.

No software to install Free Works on any device

Steps to Inspect a MAC Address

1

1. Paste the address

Replace the sample in the box. Colons, hyphens, Cisco-style dots or no separators at all are accepted, in upper or lower case.

00:1A:2B:3C:4D:5E00-1A-2B-3C-4D-5E001a.2b3c.4d5e001A2B3C4D5E
2

2. Read the OUI

The first three bytes are the organisationally unique identifier, the prefix registered to a manufacturer.
3

3. Check assignment and type

Local means software chose the address; Universal means it came from the maker. Unicast means one device, Multicast a group.
4

4. Copy the notation you need

Pick the colon, hyphen, Cisco dot, no-separator or lowercase version from the list for your router, switch or script.

Try it now

What Is a MAC Address Lookup?

A MAC address is the 48-bit hardware address a network card uses on a local network. Its first 24 bits, the OUI, are assigned by the IEEE to a manufacturer. Two bits in the first byte carry flags: one marks a locally administered address, the other a multicast address.

This page decodes those parts. It does not ship the IEEE's large registry file, so it shows the prefix to search for rather than naming the company. Search the OUI on the IEEE's public listing to see the maker.

Why Use IP and Network Calculators?

Subnet masks, CIDR ranges and download times all come down to binary maths that is easy to slip on. These calculators do the sums in the page, so you can plan an address range or check a speed claim with confidence.

“One wrong subnet mask can take a whole office offline.”

Subnets worked out instantly
CIDR ranges made clear
Download times estimated
Browser details revealed

Usable host counts shown
IPv4 and IPv6 conversions
MAC addresses checked
No commands to install

Popular Uses for Subnet Calculators

Network jobs at home and at work often start with one of these sums.

Planning an office network Split an address block into subnets for each floor, team or guest WiFi.
Reading CIDR notation See the first address, last address and host count behind a range like /24.
Download estimates Work out how long a large file will take on a given connection speed.
Speed claims Turn megabits per second into megabytes to see what a plan really delivers.
Device lookups Find the maker of a network card from its MAC address prefix.
Browser checks See your user agent and browser details when a support team asks.
WebSocket tests Connect to a WebSocket endpoint and watch messages go back and forth.
IPv6 planning Convert an IPv4 address into IPv6 form while preparing a migration.

What the MAC Decoder Shows

Manufacturer prefix

The OUI is split out and formatted, ready to paste into the IEEE registry search or a vendor lookup site.

Randomised address check

A locally administered result usually means a phone or laptop using a private, randomised Wi-Fi address.

Five notations

Colon separated, hyphen separated, Cisco dotted, no separator and lowercase, each shown in full.

Clear error message

Anything that is not twelve hex digits is flagged, with a note on which separators are accepted.

Why Use ToolXkit for MAC Address Lookup?

Your files stay with you

Everything runs inside your browser. Nothing you open or type is uploaded to a server.

Network Tools for Different Users

Network administrators

Plan subnets, check CIDR ranges and size links for expected bandwidth.

Networking students

Practise subnetting for CCNA and other exams, and check answers quickly.

Developers

Test WebSocket servers, parse user agents and inspect TCP header fields.

IT support staff

Collect browser details and estimate transfer times while helping users.

Small office owners

Understand router settings and IP ranges without calling a technician every time.

Streamers and gamers

Check upload speed, latency and packet loss figures before a stream.

Best Times to Work Out a Subnet

Network calculators help when you are:

Setting up a new router
Studying for a networking exam
Adding a guest WiFi network
Estimating a large upload
Comparing broadband plans
Identifying an unknown device
Moving to IPv6
Debugging a WebSocket connection

Tips for Identifying Devices by MAC

Unknown device on your Wi-Fi showing a Local address? It is probably a phone with private addressing turned on, not an intruder.
To name the maker, search the OUI shown here on the IEEE Registration Authority's public listing.
MAC filtering on a router is weak security. Addresses are easy to copy, so use a strong Wi-Fi password as well.
Cisco switches expect the dotted form, while Windows shows hyphens and Linux uses colons. Copy the matching notation to avoid typos.
Found on a sticker? The address printed on a router usually belongs to one port; the others often count up by one.

Frequently Asked Questions

Answers to common questions about this tool.

Can I find the manufacturer from a MAC address here?

The page extracts the manufacturer prefix but does not name the company, because the IEEE's registry is a large file that is not bundled. Copy the OUI shown and search it on the IEEE's public listing to see who registered it.

Why does my phone have a different MAC on each Wi-Fi network?

Modern Android and iPhone models use a private, randomised address per network to stop tracking. Those addresses have the locally administered bit set, which this tool shows as Local.

Can a MAC address reveal my location?

Not by itself. It is only visible on the local network you are connected to and does not travel across the internet, so websites you visit never see it.

How do I find my own MAC address?

On Windows, run ipconfig /all in Command Prompt and look for Physical Address. On a Mac, open System Settings, Network, then Details. On Android and iPhone it is under Wi-Fi settings for the connected network.

Is the address I type sent anywhere?

No. Decoding happens in your browser with simple bit checks. Nothing is looked up online, so the address stays on your device.

Is MAC Address Lookup accurate enough for real network work?

The maths behind addresses and ranges is exact, so the results match what a router expects. Double-check the input, especially the prefix length, since one wrong digit changes the whole range.

Do the calculators scan my network?

No. The subnet and speed calculators only work with the numbers you type in. They send no traffic into your network, and the only tool that connects anywhere is the WebSocket Tester, to the address you enter.

Why is my real download slower than the estimate?

The calculator assumes the full connection speed is available. In practice, WiFi, other devices, server limits and protocol overhead eat into it, so real downloads often take somewhat longer.

Is MAC Address Lookup free and private?

Yes. It costs nothing and needs no account. What you type stays in your browser and is never sent to ToolXkit, which matters when it describes a real company network.

What is the difference between Mbps and MBps?

Mbps means megabits per second, the unit broadband plans use. MBps means megabytes per second, the unit most download windows show. One byte is eight bits, so 100 Mbps is about 12.5 MBps.

More Internet & Network Tools

Other free tools for the same kind of job.

Browse all tools