OpenID Connect ID Token (JWT) Regex for PHP

What this pattern does

This page provides a well-structured, multi-part regular expression for matching openid connect id token (jwt), ported and verified for PHP. 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 PHP project — whether you're validating in a Laravel validator, a WordPress plugin, or a standalone PHP script.

Php Implementation

<?php
// OpenID Connect ID Token (JWT)
// ReDoS-safe | RegexVault — Security > OAuth & OIDC

define('OPENID_CONNECT_ID_TOKEN_JWT_PATTERN', '/^([A-Za-z0-9_-]+)\.([A-Za-z0-9_-]+)\.([A-Za-z0-9_-]*)$/');

function validate_openid_connect_id_token_jwt(string $input): bool {
    return (bool) preg_match(OPENID_CONNECT_ID_TOKEN_JWT_PATTERN, $input);
}

// Example
var_dump(validate_openid_connect_id_token_jwt("eyJhbGciOiJSUzI1NiJ9.eyJzdWIiOiJ1c2VyMTIzIiwiYXVkIjoiY2xpZW50XzEifQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c")); // bool(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 PHP developers because especially relevant in PHP where PCRE backtracking limits can trigger silent failures on malicious input. 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

OIDC ID tokens are JWTs with specific required claims: iss (issuer), sub (subject), aud (audience), exp (expiry), iat (issued at). Always validate: 1) signature, 2) iss matches expected provider, 3) aud matches client_id, 4) exp is in the future, 5) nonce (if used). Never trust an ID token without validation.