How to choose the right accessibility testing approach for test automation

In our earlier article, Building accessibility into quality with test automation, we illustrated practical ways to add accessibility checks to existing test automation for quick wins. This follow-up article takes the next step: comparing accessibility scanning engines to help development teams choose the tool that best fits their needs. 

This post focuses explicitly on a comparative analysis of axe-core and IBM Equal Access Accessibility Checker. We chose these two because both can be integrated directly into existing end-to-end test automation workflows, especially with tools such as Playwright and Cypress. That matters because it allows teams to run accessibility checks not only on a page URL, but also on the application in a specific state after the test has already performed certain user actions. In practice, that means you can scan the UI after opening a modal, expanding an accordion, completing a form step or navigating through a workflow —exactly where many accessibility issues surface. 

There are other strong accessibility tools worth considering, including  QualWeb or Pa11y. However, they are not the focus of this comparison because they are less aligned with the use case discussed here: embedding accessibility checks into an existing E2E test suite. Pa11y is primarily positioned as a command-line and Node.js tool for testing pages separately, while QualWeb is generally used through its own automation flow rather than as a lightweight in-test scanner. That does not mean these tools are weaker. It simply means they are a less natural fit when the goal is to run accessibility checks inside the same test process and on the same page state already managed by Playwright or Cypress. 

With that scope in mind, this article compares axe-core and IBM Equal Access across the criteria that matter most in practice: 

 

• Detection philosophy and the balance between strictness and false positives  
• Configurability, including rule selection and scoping  
• Integration into existing test automation workflows  
• Reporting, triage and handling of legacy issues  
• The kinds of teams and projects each tool fits best 

 

At a glance: Which tool fits best?

 

Although the article is a detailed one, if you prefer a summarized version of this analysis, this is tabulated below: 

 

 

However, if you would appreciate the efforts and a more comprehensive analysis, the rest of the article explains each of these differences in detail.

 

An overview of axe-core and IBM Equal Access

 

axe-core is one of the most widely used accessibility testing engines. It powers numerous commercial tools, browser extensions and CI integrations. Its rule set aligns closely with WCAG and ARIA requirements, and it is widely regarded as stable, mature and relatively conservative to reduce false positives. 

 

One of its biggest strengths is configurability, where teams can scope scans to specific components, include or exclude individual rules and adapt the engine to fit their existing testing strategy. For Playwright, the axe-core integration is documented in their official accessibility guide (opens in a new tab). For Cypress, documentation on using cypress-axe (opens in a new tab) is available. Additionally, Cypress Accessibility — a premium plugin — offers enhanced axe-core integration within the Cypress UI, though it requires a paid license. In addition to the scanning engine itself, Deque also provides axe for Designers for Figma, which helps teams catch common accessibility issues and improve design-to-development handoff earlier in the process. 

 

IBM Equal Access is IBM’s accessibility testing engine for enforcing WCAG requirements together with IBM’s internal accessibility standards. Compared to axe-core, it tends to surface a broader set of issues because it applies stricter interpretations in some areas. While it is less flexible in day-to-day configuration, it provides strong reporting and consistent enforcement. Rules can be disabled, but fail levels are more rigid once configured. 

 

A notable strength of IBM Equal Access is its support for baselines, which is especially useful for legacy applications. A baseline allows teams to distinguish between existing issues and newly introduced ones, so future scans focus on regressions and deltas rather than repeatedly surfacing the same known backlog. This can make adoption more practical in large or long-lived projects, where fixing all historical issues at once is often unrealistic. 

 

Similarly, IBM also provides the IBM Accessibility Design Kit for Figma and Sketch, which can help teams bring accessibility guidance into the design phase and support a smoother handoff into implementation. 

 

Comparing configuration and control capabilities 

 

Flexibility vs. Strictness: axe-core emphasizes flexibility, allowing teams to adapt the engine to their specific testing needs. IBM Equal Access takes a more opinionated approach, applying stricter defaults and offering fewer override options. 

 Rule inclusion and exclusion: axe-core supports selective inclusion and exclusion of rules, with configuration passed directly into functions such as analyze() or checkA11y(). This makes it easy to adapt checks to different contexts within the same test suite. IBM Equal Access allows rules to be disabled, but it does not support selective inclusion or different rule sets for specific components. Configuration is typically handled centrally through files such as .achecker.yml or aceconfig.js in the project root. 

 

Component-level scoping: axe-core provides a dedicated and well-documented scoping mechanism through include and exclude selectors, allowing tests to target specific DOM areas or components. This makes it particularly well suited for component-level testing, design systems, and isolated UI scenarios. IBM Equal Access does not offer an equivalent high-level scoping API. Its public getCompliance() method evaluates the DOM node passed to it, so it can technically analyze a specific subtree when given a node other than document. However, this behavior is not presented as an official scoping feature, and the Cypress and Playwright integrations do not expose comparable scoping options. In practice, that makes scoping possible only in a more manual, low-level way, whereas axe-core provides a more fully supported workflow. 

 

Fail levels: IBM Equal Access introduces fail levels that categorize issues by severity and provide stronger built-in enforcement once configured.  axe-core does not impose this model directly, leaving severity handling to the surrounding test framework or CI pipeline. 

 

Differences in detection — and how these matter 

 

In terms of a detection philosophy, axe-core follows a relatively conservative detection strategy, aiming to reduce false positives and keep automated results easier to act on. IBM Equal Access applies stricter interpretations in some areas, which can surface a broader set of findings but may also require more human judgment during triage. 

 

Both engines detect many of the same core accessibility problems, including structural issues such as ARIA misuse, labeling problems and color contrast failures. IBM Equal Access often adds warnings or recommendations that go beyond strictly actionable failures, highlighting areas that may deserve closer inspection from an accessibility perspective. 

 

When considering false positives and developer experience, axe-core’s conservative approach can make adoption easier for development teams, especially when accessibility checks are being introduced into existing pipelines for the first time. IBM Equal Access may require more manual verification because of its stricter and sometimes broader findings, but that trade-off can be valuable for teams that want stronger enforcement and are prepared to review results more closely. 

 

Maintenance, communities and governance

 

axe-core benefits from a large open-source community, frequent updates and broad adoption across the accessibility and testing ecosystem. That maturity makes it easier to find examples, third-party integrations and community knowledge when teams run into implementation questions. IBM Equal Access is maintained by IBM, and receives regular updates aligned with IBM’s internal accessibility standards and initiatives. While its public community is smaller than axe-core’s, it offers a more enterprise-centered model with strong governance and long-term consistency. 

 

Ecosystem integrations

 

axe-core has a broader ecosystem overall, with integrations spanning Cypress, Playwright, Jest, Storybook, browser extensions and many commercial tools. IBM Equal Access has a narrower but still practical integration story for the use case discussed in this article, especially through its Cypress support and its npm package for Playwright-based workflows. 

 

And finally, which do you choose? 

 

Both axe-core and IBM Equal Access are strong accessibility testing engines, but they are optimized for somewhat different priorities. axe-core is the better fit for teams that value flexibility, precise scoping and tight integration into existing test automation workflows. It is especially well suited for teams that want to tailor accessibility checks to different contexts and keep control over how findings are enforced in CI. IBM Equal Access is the better fit for teams that prefer stricter defaults, stronger built-in enforcement and support for working with legacy applications through baselines. It may require more manual review, but that trade-off may be worthwhile in environments where broader detection and structured governance are more important than maximum flexibility. 

 

"For some teams, the strongest approach may even be to use both engines in complementary ways: axe-core for targeted, flexible integration into automated workflows, and IBM Equal Access for stricter enforcement and broader review."

 

"The right choice ultimately depends less on which engine is “better” in absolute terms and more on which one best fits the way your team builds, tests and maintains software."