TLS Client Hello Mirror

Your browser's TLS Client Hello, reflected as JSON

This test:

• reflects the complete Client Hello message, preserving the order in which TLS parameters and extensions are sent;
• can be used to check for TLS privacy pitfalls (session resumption, TLS fingerprinting, system time exposure);
• supports both HTTP and Gemini;
• is free as in freedom and trivial to self-host.

Endpoints

• json/v1 - basic
• json/v2 - detailed

JSON only, for now. The API is largely stable - fields may be added, but existing fields will not be modified or removed. See the documentation for details.