ACT Rules Accessibility Checker

The W3C Accessibility Conformance Testing (ACT) Rules are a collection of standardized test procedures developed by the W3C ACT Task Force to ensure consistent, reproducible accessibility testing across different tools and auditors. Each ACT Rule defines a specific test — including the input (what to test), applicability (which elements to test), expectations (what constitutes a pass or fail), and the WCAG success criteria being evaluated. As of 2024, there are over 80 published ACT Rules covering a wide range of WCAG success criteria. ACT Rules are implementation-agnostic: they describe what to test, not how a specific tool should implement the test. This means different accessibility testing tools implementing the same ACT Rule should produce identical results on the same content, solving the long-standing problem of inconsistent results between scanners.

Before ACT Rules, accessibility testing was notoriously inconsistent. Studies showed that different automated tools could disagree on up to 40% of test results for the same page, and manual auditors also reached different conclusions. This inconsistency created problems for organizations trying to demonstrate compliance — a site might pass one tool's test but fail another's. ACT Rules address this by:

• Standardizing test definitions: Each rule has a precise specification including edge cases and exceptions, eliminating ambiguity about what constitutes a violation
• Enabling tool comparison: The ACT Rules Community Group maintains an implementation report showing how well each tool implements the rules, creating transparency and accountability
• Supporting regulatory consistency: EU regulators have adopted ACT Rules as part of the Web Accessibility Directive monitoring methodology, ensuring consistent assessment across member states
• Providing legal defensibility: Test results based on standardized ACT Rules are more defensible in legal proceedings than proprietary test logic

Major accessibility tools including axe-core, WAVE, and Lighthouse have aligned their rules with ACT, and EU member state monitoring bodies use ACT Rules for their periodic audits.

ACT Rules cover the WCAG success criteria that can be reliably tested programmatically:

• Images and alt text: Rules for img elements, SVG graphics, role="img" elements, and image buttons — testing for meaningful text alternatives (WCAG 1.1.1)
• Color and contrast: Rules for text contrast ratios against backgrounds, including considerations for gradients, images behind text, and opacity (WCAG 1.4.3, 1.4.6)
• Forms and labels: Rules for input labeling through <label>, aria-label, aria-labelledby, and title attributes (WCAG 1.3.1, 4.1.2)
• Page structure: Rules for document language (lang attribute), page titles, heading hierarchy, and landmark regions (WCAG 2.4.1, 2.4.2, 3.1.1)
• Links and navigation: Rules for link purpose from context, redundant links, and skip navigation mechanisms (WCAG 2.4.4)
• ARIA usage: Rules for valid ARIA roles, required ARIA attributes, and proper state management (WCAG 4.1.2)

Each rule includes detailed test cases — both passing and failing examples — that tool developers use to verify their implementations are correct.

CompliScan's scanner uses axe-core, which implements a large subset of W3C ACT Rules. Axe-core is one of the most ACT-aligned accessibility testing engines, with published conformance results in the W3C implementation report. When CompliScan detects a violation, the underlying test is backed by a standardized ACT Rule specification, meaning your results are consistent, reproducible, and defensible. Each finding references the specific WCAG criterion and, where applicable, the ACT Rule ID (e.g., bc659a for image alt text). This is particularly valuable for organizations operating under the European Accessibility Act or the US ADA Title II deadline of April 24, 2026, where demonstrating systematic, standards-based testing strengthens your compliance position. Our AI engine adds context by explaining why each rule matters and generating fix suggestions tailored to your specific code. Start with a free scan, or deploy Agency ($299/mo) to monitor up to 50 sites with ACT-backed testing.