Singapore Postal Code Regex for JavaScript

What this pattern does

This page provides a well-structured, multi-part regular expression for matching singapore postal code, 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 Postal Code
// ReDoS-safe | RegexVault — Localization > Postal Codes

const singaporePostalCodeRegex = /^(0[1-9]|[1-7][0-9]|8[0-2])[0-9]{4}$/;

function validateSingaporePostalCode(input: string): boolean {
  return singaporePostalCodeRegex.test(input);
}

// Example
console.log(validateSingaporePostalCode("018956")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Localization > Postal Codes 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 postal sectors run 01-82. The first two digits identify the area: 01-08 (Central), 09-11 (Orchard), 57-58 (Yishun), etc. Singapore has a geographically compact but dense postal grid.