The AInspector tool is a free sidebar utility on Firefox that provides a summary of violations divided by WCAG rule category. It maps the violated WCAG guideline to the suggested violation. AInspector was developed at the University of Illinois (UIUC).
ANDI is a free tool developed by the federal government to test websites for accessibility, run by technologists at the Social Security Administration. It provides automated detection of accessibility issues and reveals how screen reader interprets interactive elements. ANDI gives practical suggestions to improve accessibility and check 508 compliance.
A free tool developed by Utah State University to check your website for Web Content Accessibility Guideline (WCAG) errors
When providing downloadable documents there are steps you can follow to ensure accessibility for all users. Below are some curated resources that explain how to create accessible documents in multiple formats: