Wikipedia is a multilingual, web-based and free-content encyclopaedia project based on an openly-editable model. Wikipedia has a meta page for discussion about the accessibility of its web pages.
WAVE has detected 2 accessibility errors of the
Wikipedia main page (Figure 16: Wikipedia Accessibility Evaluation by WAVE).
(Table 4: Wikipedia Accessibility Evaluation by FAE) shows Wikipedia Accessibility Evaluation by FAE. There are 50 errors with Styling and only 5 errors with Navigation and Orientation.
Wikipedia got 90% when assessed by SortSite tool (Figure 17: Wikipedia Accessibility Evaluation by SortSite). This tool offers various checkpoints for the accessibility and usability of web sites. (Figure 18: Wikipedia Accessibility Evaluation by SortSite-Summary Page) shows that the Overall Quality of Wikipedia is worse than average. However, Errors (Figure 19: Wikipedia Accessibility Evaluation by SortSite-Errors Page) and Compliance (Figure 20: Wikipedia Accessibility Evaluation by SortSite-Compliance Page) issues are better than average. Finally, the Overall accessibility evaluation of Wikipedia is worse than average (Figure 21: Wikipedia Accessibility Evaluation by SortSite-Accessibility Page).
In visualization view (Figure 22: Visualization View of Wikipedia by aDesigner), it is confirmed that most parts of the page are dark-collared. Blind users have to wait too long to visit these fragments, whereas Low Vision users do not have problem. The aDesigner tool states that Wikipedia is almost compliant with guidelines with some errors (Figure 23: Visualization Result of Wikipedia by aDesigner).
Wikipedia was tested by some tools of W3C; namely Markup and CSS Validation. Although Wikipedia was successfully checked as XHTML 1.0 transitional (Figure 24: Wikipedia Accessibility Evaluation by W3C-Markup Validation Page), SortSite tool shows in (Figure 26: Wikipedia Accessibility Evaluation by SortSite-Standards Page) that some pages fail W3C HTML/XHTML validation. In addition, W3C CSS Validator found 69 errors and 23 warnings (Figure 25: Wikipedia Accessibility Evaluation by W3C-CSS Validation Page). In general, Wikipedia has a standard design and a good style (Figure 26: Wikipedia Accessibility Evaluation by SortSite-Standards Page).
Wikipedia works perfectly with most popular browsers such as Internet Explorer, Firefox, Safari, Opera and Chrome (Figure 27: Wikipedia Accessibility Evaluation by SortSite-Compatibility Page). Moreover, I have tested Wikipedia main page by BrowserCam Tool with more than 20 different mix environments between Operating Systems such as Windows, Linux and Mac and Browsers such as Internet Explorer, Firefox, Safari, Opera and Chrome (Figure 29: Wikipedia in various browsers and OP’s by BrowserCam).
(Figure 28: Wikipedia Accessibility Evaluation by SortSite-Usability Page) shows the result of Wikipedia usability by SortSite evaluation tool. Although there are a few pages that violate Usability.gov Guidelines, Wikipedia has no problem issues with W3C Best Practices and Readability. Generally speaking, it is easy to find the information you are looking for most of the time and to see where you are on a site, where you have been, and where you want to go. Menus are organized with a quite simple style that allows all users to work with it easily.