Generic Bearer Token (Authorization Header) Regex for PHP

What this pattern does

This page provides a well-structured, multi-part regular expression for matching generic bearer token (authorization header), 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
// Generic Bearer Token (Authorization Header)
// ReDoS-safe | RegexVault — Security > API Keys & Tokens

define('GENERIC_BEARER_TOKEN_AUTHORIZATION_HEADER_PATTERN', '/^Bearer\s+([A-Za-z0-9\-._~+\/]+=*)$/');

function validate_generic_bearer_token_authorization_header(string $input): bool {
    return (bool) preg_match(GENERIC_BEARER_TOKEN_AUTHORIZATION_HEADER_PATTERN, $input);
}

// Example
var_dump(validate_generic_bearer_token_authorization_header("Bearer eyJhbGciOiJSUzI1NiJ9.abc.def")); // bool(true)

Test Cases

When to use this pattern

This pattern is drawn from the Security > API Keys & Tokens 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

RFC 6750 Bearer token format. The token itself is an opaque string — not validated structurally here. The character set covers base64url, standard base64, and common token formats. Use downstream pattern to validate the token type (JWT, opaque, etc.).