Mac Address Regex Javascript Validator

What is MAC Address Regex?

A MAC (Media Access Control) address is a unique identifier assigned to network interfaces. It typically appears in the format 00:1A:2B:3C:4D:5E or 00-1A-2B-3C-4D-5E, using hexadecimal digits separated by colons or hyphens.

In JavaScript, we can use regular expressions (regex) to verify whether a string follows this structure before using it in networking, device identification, or access filtering.

MAC Address Regex Pattern

The commonly used regex to validate MAC addresses is:

^([0-9A-Fa-f]{2}[:-]){5}([0-9A-Fa-f]{2})

This matches:

• Six groups of two hexadecimal characters

• Separated by either : or -

• Case-insensitive (thanks to [A-Fa-f])

How to Validate MAC Address using Regex in JavaScript

Here’s a full JavaScript example:

function isValidMacAddress(mac) {
  const macRegex = /^([0-9A-Fa-f]{2}[:-]){5}([0-9A-Fa-f]{2})$/;
  return macRegex.test(mac);
}

console.log(isValidMacAddress("00:1A:2B:3C:4D:5E")); // true
console.log(isValidMacAddress("00-1A-2B-3C-4D-5E")); // true
console.log(isValidMacAddress("001A.2B3C.4D5E"));    // false

Real-World Use Cases

• Network configuration: Validate MAC addresses before storing or using them in router or server config tools.

• Device management: Identify and verify devices in IoT ecosystems.

• Access control: Allow or block specific MACs in security-sensitive systems.

• Form input validation: Make sure users don’t enter invalid MAC formats in web applications.

Pro Tips

• Always trim whitespace from input strings before validation.

• Regex is for format checking, not legitimacy. A syntactically valid MAC address may still not exist.

• Support both : and - formats if your application handles different sources.

• Consider using Base64 Encoder for secure storage or transmission.

• Use this in combination with Token Generator to assign unique device tokens post-validation.

JavaScript Metacharacters Used

• ^ : Anchors the regex at the start of the string.

• $ : Anchors the regex at the end of the string.

• [0-9A-Fa-f] : Matches a single hexadecimal character (case-insensitive).

• {2} : Quantifier – exactly 2 characters.

• [:-] : Matches either ':' or '-'.

• {5} : Quantifier – matches the group 5 times.

• (…) : Capturing group.

Example Regex Inputs

1. "01:23:45:67:89:AB" → Valid

2. "01-23-45-67-89-AB" → Valid

3. "0123.4567.89AB" → Invalid

4. "G1:23:45:67:89:ZZ" → Invalid

Combine with These Tools

Use this MAC Address Validator alongside:

• IP Address Regex JavaScript Validator: To validate full device network identity.

• UUID Regex JavaScript Validator: To validate system-assigned unique IDs.

• Base64 Decoder: Decode network data payloads after encryption.