HTTP Strict-Transport-Security Header Regex for JavaScript

What this pattern does

This page provides a well-structured, multi-part regular expression for matching http strict-transport-security header, ported and verified for JavaScript. In security-sensitive code, using an unverified regex can open the door to both false positives and denial-of-service attacks. 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

// HTTP Strict-Transport-Security Header
// ReDoS-safe | RegexVault — Security > Security Headers

const httpStricttransportsecurityHeaderRegex = /^max-age=([0-9]+)(?:;\s*includeSubDomains)?(?:;\s*preload)?$/i;

function validateHttpStricttransportsecurityHeader(input: string): boolean {
  return httpStricttransportsecurityHeaderRegex.test(input);
}

// Example
console.log(validateHttpStricttransportsecurityHeader("max-age=31536000")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Security > Security Headers 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

HSTS tells browsers to only connect via HTTPS. min max-age for HSTS preloading: 31536000 (1 year). max-age=0 disables HSTS. includeSubDomains extends to all subdomains. preload submits to Chrome/Firefox preload lists — be careful, it is very hard to undo. Capture group 1: max-age value in seconds.