Browser Fingerprint Hash Regex for Python

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching browser fingerprint hash, ported and verified for Python. Identity and credential patterns need both correctness and safety, since they're frequent targets for adversarial input. 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

# Browser Fingerprint Hash
# ReDoS-safe | RegexVault — Identity & PII > Digital Identity

import re

browser_fingerprint_hash_pattern = re.compile(r'^[0-9a-f]{32}$|^[0-9a-f]{64}$')

def validate_browser_fingerprint_hash(value: str) -> bool:
    return bool(browser_fingerprint_hash_pattern.fullmatch(value))

# Example
print(validate_browser_fingerprint_hash("d41d8cd98f00b204e9800998ecf8427e"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Identity & PII > Digital Identity 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

Browser fingerprinting combines canvas, WebGL, fonts, plugins, and device characteristics into a hash. Under GDPR recital 30, fingerprinting constitutes tracking. Under ePrivacy Directive, it requires consent. 32 chars = MD5, 64 chars = SHA-256.