Brazilian Phone Number Regex for JavaScript

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching brazilian 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

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

const brazilianPhoneNumberRegex = /^(?:\+55\s?)?(?:\(?([1-9][1-9])\)?\s?)(?!\1\s?9[0-9]{8}$|11\s?987654321$)(?:9[0-9]{4}-[0-9]{4}|[2-9][0-9]{3}-[0-9]{4}|9[0-9]{8}|[2-9][0-9]{7})$/;

function validateBrazilianPhoneNumber(input: string): boolean {
  return brazilianPhoneNumberRegex.test(input);
}

// Example
console.log(validateBrazilianPhoneNumber("+55 11 98765-4321")); // 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

Brazilian DDD codes are 2 digits (11=São Paulo, 21=Rio de Janeiro, etc.). Mobile numbers have 9 digits starting with 9; landlines have 8 digits. +55 is the country code. All mobiles received a 9th digit in 2012-2016.