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...
Burp Suite : Burp Suite is an integrated platform for performing security testing of web applications. Its various tools work seamlessly together to support the en...
aXe : Automated tool to find Accessibility defects on your web site by using the aXe Chrome extension. Drop the aXe on your accessibility defects! We believ...
Monitor the accessibility of your websites with pa11y-dashboard, and protect against accessibility errors creeping into your codebase.