What is the disadvantage of using automated accessibility testing tools?

Automated accessibility testing tools play a crucial role in identifying potential accessibility issues within digital content, but they have inherent limitations. One significant disadvantage is that these tools do not fully capture user experience issues. While they can effectively highlight many common accessibility problems such as missing alt text or improper heading structures, they are unable to assess the nuances of how users interact with a system, nor can they account for context-based experiences that vary greatly among individuals.

For instance, automated tools might overlook the subtleties of how users with different disabilities might navigate a website or application, such as understanding the meaning of content through context or experiencing difficulty with the user interface design. Accessibility is not solely about compliance with specific guidelines; it is about creating an inclusive experience that meets the diverse needs of users. Manual testing, which involves real users and usability studies, provides insights that automated tools cannot achieve, thereby highlighting the necessity of combining both approaches for a comprehensive accessibility assessment.