Learn how Auth0 is using JA4 fingerprinting to defeat sophisticated bots, bypass TLS spoofing, and improve TLS security for your applications without code changes.

Auth0's platform is a  identity management solution, offering insights into authentication, authorization, and user management for web and mobile applications. Through articles, tutorials, and documentation, Auth0 offers insights into securing applications with modern identity protocols like OAuth and OpenID Connect. Developers can learn about implementing single sign-on (SSO), multi-factor authentication (MFA), and user authorization policies to enhance application security and user experience.

Auth0

Auth0 has integrated JA4 TLS fingerprinting as a signal into its Bot Detection ML model. Unlike the older JA3 standard, JA4 sorts and normalizes TLS extensions before hashing, making fingerprints stable even when modern browsers like Chrome and Firefox randomize extension order. This allows Auth0 to detect bots that spoof User-Agent strings or rotate residential IPs, since automated scripts share the same JA4 signature regardless of IP. Key benefits include identifying headless browser automation (Puppeteer, Playwright), detecting distributed credential stuffing attacks, and reducing false positives — all without requiring any code changes from customers.

Strengthening Bot Detection with JA4 Signals

Why We Added JA4 as a Signal to Bot Detection

How JA4 as a Signal Strengthens Your Bot Defense