FTP URL Regex for JavaScript

What this pattern does

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

// FTP URL
// ReDoS-safe | RegexVault — Web & Network > URL

const ftpUrlRegex = /^ftps?:\/\/(?:[a-zA-Z0-9._~!$&'()*+,;=%-]+(?::[a-zA-Z0-9._~!$&'()*+,;=%-]*)?@)?(?:[a-zA-Z0-9\-]+\.)+[a-zA-Z]{2,63}(?::[1-9][0-9]{0,4})?(?:\/[^\s]*)?$/i;

function validateFtpUrl(input: string): boolean {
  return ftpUrlRegex.test(input);
}

// Example
console.log(validateFtpUrl("ftp://files.example.com")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Web & Network > URL 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

Credentials in URLs are a security risk — prefer separate authentication mechanisms. FTPS (FTP over SSL) typically uses port 990.