Automated web accessibility testing tools have been found complementary. The implication: To catch as many issues as possible, use multiple tools. Doing this efficiently entails integration costs. Is there a small set of tools that, together, make additional tools redundant? I approach this problem by comparing nine comprehensive accessibility testing tools that are amenable to integration: alfa, axe-core, Continuum, Equal Access, HTML CodeSniffer, Nu Html Checker, QualWeb, Tenon, and WAVE. I tested 121 web pages of interest to CVS Health with these tools. Each tool only fractionally duplicated any other tool. Each discovered numerous issue instances missed by all the others. Thus, testing with all nine tools was substantially more informative than testing with any subset.

翻译：自动化的网页无障碍测试工具被发现具有互补性。这意味着：为了尽可能多地发现问题，应使用多种工具。高效执行此操作需要集成成本。是否存在一小组工具，使得其他工具变得多余？我通过比较九种易于集成的综合无障碍测试工具（包括：alfa、axe-core、Continuum、Equal Access、HTML CodeSniffer、Nu Html Checker、QualWeb、Tenon 和 WAVE）来探讨这一问题。我用这些工具测试了 CVS Health 关注的121个网页。每种工具仅与其他工具存在部分重复检测结果，且每种工具都发现了其他工具遗漏的大量问题实例。因此，使用全部九种工具进行测试比使用任何子集获取的信息量都显著更多。