↓ download on github


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 some cryptographic flaws.

Key features

  • Clear output: you can tell easily whether anything is good or bad.
  • Machine readable output.
  • No installation needed: Linux, OSX/Darwin, FreeBSD, NetBSD, MSYS2/Cygwin, WSL work out of the box. Only OpenBSD needs bash. No need to install or to configure something. No gems, CPAN, pip or the like.
  • A Dockerfile is provided, there’s also an offical container @ dockerhub.
  • Flexibility: You can test any SSL/TLS enabled and STARTTLS service, not only web servers at port 443.
  • Toolbox: Several command line options help you to run your test and configure your output.
  • Reliability: features are tested thoroughly.
  • Privacy: It’s only you who sees the result, not a third party.
  • Freedom: It’s 100% open source. You can look at the code, see what’s going on.
  • The development is open (github) and participation is welcome.


This software is free. You can use it under the terms of GPLv2, see LICENSE. In addition starting from version 3.0rc1 if you’re offering a scanner based on testssl.sh as a public and / or paid service in the internet you need to mention to your audience that you’re using this program and where to get this program from.


testssl.sh is working on every Linux/BSD distribution out of the box. Latest by 2.9dev most of the limitations of disabled features from the openssl client are gone due to bash-socket-based checks. As a result you can also use e.g. LibreSSL or OpenSSL 1.1.1 . testssl.sh also works on other unixoid system out of the box, supposed they have /bin/bash >= version 3.2 and standard tools like sed and awk installed. An implicit (silent) check for binaries is done when you start testssl.sh . System V needs probably to have GNU grep installed. MacOS X and Windows (using MSYS2, Cygwin or WSL) work too.

Update notification here or @ https://twitter.com/drwetter.


You can download testssl.sh by cloning this git repository:

git clone --depth 1 https://github.com/drwetter/testssl.sh.git

Or help yourself downloading the ZIP archive https://github.com/drwetter/testssl.sh/archive/3.0.zip. testssl.sh --help will give you some help upfront. More help: see doc directory with man pages. Older sample runs are at https://testssl.sh/.

Running a docker container from dockerhub

 docker run -ti drwetter/testssl.sh <your_cmd_line>


We're currently in the late release candidate phase. That means you can and should use it for production and let us know if you encounter any additional bugs. Features implemented in 3.0 are listed in the https://github.com/drwetter/testssl.sh/CHANGELOG.md.

Support for 2.9.5 has been dropped.



Contributions, feedback, bug reports are welcome! For contributions please note: One patch per feature — bug fix/improvement. Please test your changes thoroughly as reliability is important for this project.

There’s a https://github.com/drwetter/testssl.sh/wiki/Coding-Style.

Bug reports

Please file bugs in the issue tracker @ github. Do not forget to provide detailed information, see template. Details @ https://github.com/drwetter/testssl.sh/wiki/Bug-reporting. Nobody can read your thoughts — yet. And only agencies your screen ;-)

You can also debug yourself, see https://github.com/drwetter/testssl.sh/wiki/Findings-and-HowTo-Fix-them.

External/related projects

Please address questions not specifically to the code of testssl.sh to the respective projects below.

Cool web frontend

Mass scanner w parallel scans and elastic searching the results

Another ready-to-go docker image is at:

Privacy checker using testssl.sh

Brew package

Daemon for batch execution of testssl.sh command files

Daemon for batch processing of testssl.sh JSON result files for sending Slack alerts, reactive copying etc

Tools Cryptography