In order to make sure your website complies with recognized accessibility standards, use website accessibility evaluation tools. These tools can assist you in identifying potential accessibility issues and barriers faster, and they can be used at any point during the web design and development life cycle. Tools can help you with fully automated tests as well as manual testing that needs human intervention.
Visit IT Accessibility – Testing Tools for a list of the most popular tools currently in use. For a complete list of tools, the World Wide Web Consortium (W3C) Web Accessibility Initiative (WAI) has a repository of testing tools within its Web Accessibility Evaluation Tools List.
An important thing to note is that an evaluation tool cannot verify all areas of accessibility standards automatically. It is necessary to use human judgment and discretion to determine actual errors. Evaluation tools can sometimes give inaccurate or misleading results which need validation. Web accessibility evaluation tools can only aid in testing for accessibility, not determine it.