Web Accessibility Testing Tools Part II: Web-based Accessibility Evaluators

Screenshot of a WCAG Contrast Checker tool

Welcome back to the Olenick Web Accessibility Testing Tools Blog Series! Today’s blog post will cover how and when to incorporate free, Web-based automated accessibility evaluators into overall-manual accessibility testing. Furthermore, we will discuss potential issues to be aware of when utilizing free automated testing tools for accessibility testing.


Before diving into the actual tools, it is important to first note that free, Web-based accessibility evaluators should never be used as standalone testing tools. Instead, try using a Web-based accessibility evaluator as a starting point to provide awareness on potential areas of non-compliance with WCAG 2.0. It is critical that Web-based accessibility evaluators are leveraged in conjunction with manual testing because the evaluators do not catch every accessibility issue on a Web page and also cannot evaluate abstract concepts, such as how a human will perceive particular Web content. For example, an accessibility evaluator will not be able to determine if the text on a Web page serves as an alternate form of presenting information found in a video on the same page, thus human testers are the most vital aspect of overall accessibility testing.


Having said that, accessibility evaluators do provide a great starting point for accessibility testing as they can flag potential Web accessibility issues.  In particular, WAVE (Web Accessibility Evaluation Tool) is an excellent evaluator to utilize since it shows the results of the accessibility evaluation on the front end of the tested Web page.


What’s more, WAVE provides “More Information,” and even suggested fixes, for all errors and alerts found on a given Web page as depicted in Figure 1.  These tips are invaluable, especially for people who are new to the realm of accessibility testing and may not be aware of the suggested fixes for errors and alerts. However, human accessibility testers should always manually check for more complex areas of accessibility issues. Case in point, I recently encountered a very high-traffic Web page with images that correctly had HTML “alt = “ tags, but did not have any text after the “=.”  Thus users with low or no vision have no clues about the context of the image, which is especially problematic if the image is also a hyperlink.


WAVE accessibility evaluation tool


Figure 1: WAVE results for Yahoo! Sports Web page

If you are looking for an alternative to WAVE with similar capabilities/tests, Google Chrome’s extension Accessibility Developer Tools provide a solid foundation for kicking off Web accessibility testing. With a built-in “accessibility audit” feature, users can run automated accessibility tests that return results to the user within the Developer Toolbar. This is particularly useful since users then have the option to expand the returned errors/warnings and see the specific line(s) of applicable HTML code.


Yet another useful Web-based accessibility evaluator is the WCAG Contrast Checker, which is a free add-on for Firefox. With the contrast checker, users can analyze the contrast ratios of all elements on a Web page in seconds to determine if the color scheme complies with the WCAG 2.0 rule for minimum contrast ratios of 4.5:1. This tool is a rare exception to my previously mentioned rule, never solely rely on automated tools for accessibility testing, since it would be intensely laborious to try to calculate color contrast ratios without the assistance of an automated tool.


Manual accessibility testing is laborious and employing some automated accessibility tools in conjunction with manual testing is a great strategy.  This is especially true during the initial phases of accessibility test execution since the tools quickly alert testers to accessibility issues on given Web pages and also provide valuable insight into fixing issues.


If you have any questions about this blog or are interested in learning more about Olenick’s Accessibility Services please reach out to me through my LinkedIn profile below or submit a question through Olenick’s contact us page.


Author: Steve Woods

Related Content: Accessibility Toolkit, Compliance Management, Digital Accessibility