Automated vs. Manual Testing
Automated accessibility tools catch obvious issues (missing alt text, low contrast, unlabeled inputs), but miss nuanced problems like meaningful descriptions, error-message clarity, heading logic, and real screen-reader/keyboard experience—so manual testing is essential.
If you’ve ever done an online search to look for resources to begin auditing the accessibility of your website it’s likely you’ve seen, and possibly have used, an automated accessibility testing tool. While manual testing involves a real person going through a website using assistive technology to evaluate its accessibility, automated testing uses software to scan a website’s code and flag automatically detectable issues.
What a lot of automated tools fail to convey is that using them alone will not catch off all website’s accessibility issues.
What is automated testing
Automated testing software—often a plugin or browser integration—runs a script to analyze the underlying code of a webpage or website against known accessibility rules. These tools evaluate rules that have a clear and detectable pass/fail condition that will either be met, or not met, within the code.