E.164 International Phone Number Regex for JavaScript

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching e.164 international 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

// E.164 International Phone Number
// ReDoS-safe | RegexVault — Localization > Phone Numbers

const e164InternationalPhoneNumberRegex = /^\+[1-9][0-9]{6,14}$/;

function validateE164InternationalPhoneNumber(input: string): boolean {
  return e164InternationalPhoneNumberRegex.test(input);
}

// Example
console.log(validateE164InternationalPhoneNumber("+6591234567")); // 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

E.164 is the global standard for phone numbers in international telephony. Maximum 15 digits (country code + subscriber). No spaces, dashes, or parentheses. Always store phone numbers in E.164 format.