Generic Bearer Token (Authorization Header) Regex for Python

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 Python. 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 Python project — whether you're validating in a Django view, a FastAPI endpoint, or a standalone data processing script.

Python Implementation

# Generic Bearer Token (Authorization Header)
# ReDoS-safe | RegexVault — Security > API Keys & Tokens

import re

generic_bearer_token_authorization_header_pattern = re.compile(r'^Bearer\s+([A-Za-z0-9\-._~+/]+=*)$')

def validate_generic_bearer_token_authorization_header(value: str) -> bool:
    return bool(generic_bearer_token_authorization_header_pattern.fullmatch(value))

# Example
print(validate_generic_bearer_token_authorization_header("Bearer eyJhbGciOiJSUzI1NiJ9.abc.def"))  # 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 Python developers because particularly important in Python web servers where CPU-bound regex operations can stall concurrent request handling. 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.).