MAC Address (No Separators) Regex for JavaScript

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching mac address (no separators), ported and verified for JavaScript. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your JavaScript project — whether you're validating in an Express middleware, a Next.js API route, or a client-side form.

Javascript Implementation

// MAC Address (No Separators)
// ReDoS-safe | RegexVault — Web & Network > MAC Address

const macAddressNoSeparatorsRegex = /^[0-9a-fA-F]{12}$/;

function validateMacAddressNoSeparators(input: string): boolean {
  return macAddressNoSeparatorsRegex.test(input);
}

// Example
console.log(validateMacAddressNoSeparators("001a2b3c4d5e")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Web & Network > MAC Address category and carries a ReDoS-safe certification. That matters for JavaScript developers because especially critical in long-running Node.js event loops where a ReDoS vulnerability can block the entire process. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

Used in database storage and API contexts where separators are stripped. Always re-insert separators when displaying to users.