testssl.sh

Command line tool to check TLS/SSL ciphers, protocols and cryptographic flaws

Platforms: Linux · Last verified September 6, 2026

testssl.sh is a free command line tool which checks a server’s service on any port for the support of TLS/SSL ciphers, protocols as well as recent cryptographic flaws and more.

Only use this tool against systems you own or are explicitly authorized to test — see the disclaimer.

Getting started

See the official Kali tool page and upstream homepage linked above for installation and usage details.

Commonly preinstalled on

Kali Linux

Debian-based distribution built for penetration testing and security auditing