WAVE is a free Web Accessibility Evaluation Tool from WebAIM. A user simply inputs a URL and WAVE responds with a comprehensive visual summary of the siteâ€™s accessibility. This functionality is exposed through a simple API.
The API accepts GET call specifying a URL and returns the pageâ€™s WAVE statistics, including number of errors, alerts, features, HTML5/ARIA elements, structural elements, and contrast attributes. The API is also able to return a listing of all identified WAVE items, as well as the XPath of each element to which a WAVE item is associated. The API is also able to retrieve the relevant documentation for any given WAVE item.