simple command line tool to check or monitor your https certificate

> checkssl -days=5 =>
 -> AmazonS3 -
 -> HTTP/2 with TLS v1.3 (released 2018) - latest version
 -> TLS_AES_128_GCM_SHA256 = TLS, message encrypted with AES128 GCM, hashes are SHA256
 1) * expires on 2024-07-29 11:59PM Mon (319.9 days)
 CA-2) Amazon RSA 2048 M01 expires on 2030-08-23 10:21PM Fri (2535.9 days)
 CA-3) Amazon Root CA 1 expires on 2037-12-31 1:00AM Thu (5222.0 days)
 CA-4) Starfield Services Root Certificate Authority - G2 expires on 2034-06-28 5:39PM Wed (3940.7 days)

CheckSSL has marked this as a pass result CheckSSL has marked this as a fail result

deployed on AWS Lambda

Install Locally

Great for checking lots of sites, scripting or use with private servers


docker run --rm szazeski/checkssl

Linux or Mac

wget$(uname -s)_$(uname -m).tar.gz -O checkssl.tar.gz && tar -xf checkssl.tar.gz && chmod +x checkssl && sudo mv checkssl /usr/bin/

Mac via Mac Ports

sudo port install checkssl

Mac via Homebrew

brew install szazeski/tap/checkssl

Windows Powershell

Invoke-WebRequest -outfile checkssl.tar.gz; tar -xzf checkssl.tar.gz; echo "if you want, move the file to a PATH directory like WINDOWS folder"

View github installation instructions for how to install on mac and windows

Download Releases for Windows, Mac, or Linux

View Source / Contribute New Features

Checkssl is an open source project that you can modify and use for your personal or commercial projects.

Goto checkssl on Github

Written in Go under a MIT License

Jenkins Continuous Integration Setup

Simple, no dependency command that integrates into your CI workflows

Add a build step with Execute Script


See the list of available environment variables

Other Tools to Check Out

Let's Encrypt is great way to generate free SSL certificates for your server

Qualsys SSL Lab produces detailed report of your SSL Certificate, ciphers and vulnerabilities.

Mozilla SSL Config produces ideal SSL config for various web servers.

BadSSL maintains testing servers with various issues, great for testing your monitoring setup

Illustrated TLS Connection every byte of a TLS connection explained and reproduced.


We hope you found this tool useful and would want to share it with others

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