12 Web Accessibility Evaluation Tools
WAI - Complete List of Web Accessibility Evaluation Tools
It is very important to keep in mind that to date, no web site evaluation tool has been developed that can completely replace a human being. This is because with present technology it is difficult to emulate human attributes such as common sense. In this regard, these tools should be used with caution, and the results that they produce should be interpreted in context with the web site you are evaluating. Moreover, since accessibility is a subset of usability, these tools should only be used to evaluate accessibility and not usability since, at best, they can only show you where your site is not accessible.
Source: 10 Free Web-Based Web Site Accessibility Evaluation Tools
Legend: W = W3C HTML Validator, B = BITV, S = Stanca Act, I = ITAA Web Accessibility Standards V = Own Heuristics for Visually Impaired, R = RGAA, M = Own Mobile Heuristics
I strongly recommend to use eXaminator and TAW. The first one is from Argentina, the second one from Spain, but both evaluation tools offer their interface in English.