Singapore Phone Number Regex for JavaScript

What this pattern does

This page provides a well-structured, multi-part regular expression for matching singapore phone number, 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

// Singapore Phone Number
// ReDoS-safe | RegexVault — Localization > Phone Numbers

const singaporePhoneNumberRegex = /^(?:\+65\s?)?[3689][0-9]{3}\s?[0-9]{4}$/;

function validateSingaporePhoneNumber(input: string): boolean {
  return singaporePhoneNumberRegex.test(input);
}

// Example
console.log(validateSingaporePhoneNumber("+65 9123 4567")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Localization > Phone Numbers 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

Singapore number prefixes: 3 (VoIP/Internet calling), 6 (landline), 8 (mobile), 9 (mobile). All Singapore numbers are 8 digits. +65 is the country code. Emergency numbers (999, 995) do not follow this format.