SSL Server Test : This free online service performs a deep analysis of the configuration of any SSL web server on the public Internet.
BounCA : BounCA is a tool to manage your personal SSL certificates and authorities in a central and easy to use interfaces. It provides an easy accessible web ...
Pa11y : Monitor the accessibility of your websites with pa11y-dashboard, and protect against accessibility errors creeping into your codebase.
Diagnostic.css : Diagnostic.css is a stylesheet which allows the user to test for common errors in a page's markup.
Also : https://github.com/karlgroves/diagnostic.css
Subgraph Vega : Vega is an open source platform to test the security of web applications. Vega can help you find and validate SQL Injections, Cross-Site Scripting (XS...
webhint is a linting tool that will help you with your site's accessibility, speed, security and more, by checking your code for best practices and common errors. Use the online scanner or the CLI to start checking your site for errors.