OAuth 2.0 Authorization Code Regex for JavaScript

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching oauth 2.0 authorization code, 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

// OAuth 2.0 Authorization Code
// ReDoS-safe | RegexVault — Security > OAuth & OIDC

const oauth20AuthorizationCodeRegex = /^[A-Za-z0-9\-\/_]{20,64}$/;

function validateOauth20AuthorizationCode(input: string): boolean {
  return oauth20AuthorizationCodeRegex.test(input);
}

// Example
console.log(validateOauth20AuthorizationCode("4/0AY0e-g7aBcDeFgHiJkLmNoPqRsTuVwXyZ01")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Security > OAuth & OIDC 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

Authorization codes are single-use and short-lived (typically 5-10 minutes). RFC 6749 does not specify the format — implementation-specific. Codes appear in the redirect URI as ?code=VALUE and must be exchanged immediately for an access token.