VC009 – Accessibility Compliance
Overview
Basic accessibility checks: images alt text, form labels, heading hierarchy, ARIA labels, color contrast, and keyboard navigation.
Probability that AI systems use this signal: Crawlers and generative AI pipelines consume structured and visible page signals for training and inference. Assessment-specific signals (e.g. schema, canonicals, trust cues) affect how likely a page is indexed and surfaced. The probability that this assessment's signal influences AI behavior is high when the page is in a product or compliance context.
Impact on geo compliance: Passing this assessment supports geo compliance by ensuring machine-readable and visible content meet standards that reduce the risk of wrong locale, pricing, or trust in AI-generated answers. Failing can lead to non-compliant or misleading surfacing.
What We Check
- **Missing alt:** img without alt or empty alt; −50 per image.
- **Missing form labels:** input/textarea/select; needs id+label[for=id] or wrapped in label; −40 per missing.
- **Heading hierarchy:** no headings → issue; multiple h1 → issue; skipped level (e.g. h2→h4); −50 per issue.
- **Missing ARIA:** button, a, input, select, textarea without aria-label, aria-labelledby, text content, title, or (for input) associated label; −30 per.
- **Color contrast:** elements with inline style with "color:" but no "background-color:" and no class/id; "Element relies only on color for information"; −20 per.
- **Keyboard:** tabindex="-1" on interactive elements; onclick on non-button/link; −30 per. Score capped at 0.
Pass / Fail and Score
- **PASSED** if score >= 60.
How to Fix When It Fails
- Add alt to images; add labels to form elements; fix heading hierarchy; add ARIA labels; improve color contrast; ensure keyboard accessibility (avoid tabindex=-1, use button/link for onclick).
Common Issues
- Images without alt; unlabeled inputs; multiple h1 or skipped levels; interactive elements without accessible name; color-only distinction; non-keyboard-accessible controls.
Dependencies
None.
How to Verify
- Manual or automated a11y audit (e.g. axe); check headings, labels, ARIA, keyboard tab order.
Additional Resources
- WCAG 2.1: https://www.w3.org/WAI/WCAG21/quickref/
- ARIA: https://www.w3.org/WAI/standards-guidelines/aria/