Bitcoin Address (P2SH — starts with 3) Regex for JavaScript

What this pattern does

This page provides a well-structured, multi-part regular expression for matching bitcoin address (p2sh — starts with 3), ported and verified for JavaScript. Financial data validation has zero tolerance for false negatives — a missed invalid entry can corrupt downstream calculations. 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

// Bitcoin Address (P2SH — starts with 3)
// ReDoS-safe | RegexVault — Finance > Crypto

const bitcoinAddressP2shStartsWith3Regex = /^3[a-km-zA-HJ-NP-Z1-9]{25,34}$/;

function validateBitcoinAddressP2shStartsWith3(input: string): boolean {
  return bitcoinAddressP2shStartsWith3Regex.test(input);
}

// Example
console.log(validateBitcoinAddressP2shStartsWith3("3J98t1WpEZ73CNmQviecrnyiWrnqRhWNLy")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Finance > Crypto 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

P2SH addresses start with 3. Commonly used for multisignature wallets and wrapped SegWit (P2SH-P2WPKH). More flexible than P2PKH — can represent complex spending conditions.