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
webhint : 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 co...
SPOF-O-Matic : Chrome extension for detecting and simulating frontend Single Points Of Failure. Detects likely third-party single points of failure as you browse and...
Nikto2 : Nikto is an Open Source (GPL) web server scanner which performs comprehensive tests against web servers for multiple items, including over 6500 potent...
Wapiti : Wapiti allows you to audit the security of your web applications.
It performs "black-box" scans, i.e. it does not study the source code of the applica...
Monitor the accessibility of your websites with pa11y-dashboard, and protect against accessibility errors creeping into your codebase.