Public documentation
Scanner modules
What each scanner reads, what it outputs, and what it cannot prove.
Module inventory
| Module | Reads | Outputs | Boundary |
|---|---|---|---|
| axe/WCAG checks | Rendered DOM and computed accessibility data available to axe-core. | Confirmed issues and incomplete/review items with source rule IDs and WCAG tags. | Dynamic states, hidden routes, user journeys, custom widgets, and manual AT behaviour still need verification. |
| Broken links | Same-origin links and link targets that can be checked from the browser context. | Advisory or issue evidence for unreachable links and request failures. | Cross-origin, authenticated, rate-limited, or blocked requests can produce incomplete evidence. |
| Metadata | Document title, description, Open Graph, schema, canonical, and preview-related metadata. | Advisory results for missing or malformed metadata. | Metadata quality is not a direct WCAG conformance result. |
| Language mismatch | Document language, visible text samples, and language detection signals. | Review/advisory evidence for likely language mismatch. | Mixed-language content and short text need human confirmation. |
| Spelling | Visible text tokens and local dictionary/allowlist behaviour. | Review results for likely misspellings and skipped unsupported language states. | Brand, technical, and domain-specific vocabulary can need allowlist decisions. |
| Alt text | Image elements, accessible names, empty alt, and nearby context where available. | Confirmed or review evidence for missing or questionable alternatives. | Decorative intent and quality of alternative text require human judgement. |
| Heading structure | Rendered heading elements and order. | Review/advisory evidence about heading order and document outline. | Visual hierarchy and component semantics require context review. |
| Browser Preference QA Controls | Extension-side preview state, computed page styles, reduced-motion inventory, browser-preference inspection signals, tester observations, and QA report selection state where supported. | Manual QA evidence for zoom/resize text, text spacing, font size, reduced motion, colour scheme, forced colours, and contrast-preference scenarios. | Preview styles are extension-side review aids, not real Chrome zoom or browser-level proof unless separately evidenced. Inspection-only utilities remain labelled as such. |
| Contrast | axe contrast results and custom ambiguity checks for rendered text/background scenarios. | Confirmed axe contrast issues and strict custom findings; ambiguous findings are review/advisory. | Gradients, images, video, canvas, overlays, and complex compositing require inspection. The former Contrast Inspector UI is roadmap work and is not exposed in the active extension. |
| Diagnostics/support | Browser/runtime state, scan limitations, permissions, errors, and support context. | Operational diagnostics and limitation records. | Diagnostics are not page defects. |