TLS Client Hello Mirror

This service presents your browser's TLS Client Hello message in multiple formats. It can be used directly or in CI tests to check for TLS privacy pitfalls (session resumption, fingerprinting, system time exposure) and security shortcomings (deprecated TLS versions, weak cipher suites, missing features, etc). Details here.

API endpoints

API documentation

Connection

{{.SessionResumptionInfo}}

Client Hello

Supported features {{.FeaturesInfo}}

Supported TLS/SSL versions {{.SupportedTLSVersions}}

Cipher suites {{.SupportedCipherSuites}}

Extensions {{.Extensions}}

Supported groups {{.SupportedGroups}}

Signature algorithms {{.SignatureSchemes}}

TLS fingerprint

Parameters in the Client Hello message differ between clients, enabling servers and on-path observers to detect what browser you are likely using (down to its version, or a range of versions) by deriving its fingerprint from said parameters. Worse, if you change any TLS-related settings, your TLS fingerprint becomes specific to a much smaller group of users, possibly even to you alone.

JA3 is a simple and popular type of TLS fingerprint. NJA3 is a similar style of fingerprint which aims to improve the robustness and accuracy of JA3.