Public documentation
Data extraction
What the extension can read, what it cannot read automatically, and what can appear in local storage or exports.
What A11Y Cat can inspect
After the user launches the extension on an active tab, packaged scripts can inspect data available in the current rendered page state. That can include the active URL, title, DOM structure, visible text, accessible-name-related attributes, labels, alt text, headings, links, controls, metadata, computed styles, selectors, page language attributes, same-origin link status where checked, and runtime diagnostics.
What it does not inspect automatically
- Every authenticated journey or user role.
- Every hidden menu, dialog, error state, lazy-loaded state, delayed state, or responsive state unless visible or triggered before scanning.
- Protected cross-origin frame content blocked by browser security.
- Browser-restricted pages such as extension stores or privileged browser pages.
- Text inside images unless separately available as DOM text, alt text, metadata, or explicit screenshot review input.
- Canvas-rendered text, video captions burned into media, or implementation details absent from the current page state.
- External systems not present in the current tab.
Data types and use
| Data type | Used by | Stored? | Exported? | Limitation |
|---|---|---|---|---|
| Active page URL and title | Scan summary, history, exports, diagnostics | Possible in history/workflow state | Yes | Sensitive internal paths can appear in exports. |
| DOM, selectors, snippets | axe-core, custom modules, highlighting, issue details | Issue snapshots/history where supported | Yes | Current-state only; selectors can become stale. |
| Visible text and names | Language, spelling, link purpose, labels, headings, review checks | Issue evidence/workflow only | Yes | Hidden/image/canvas text may be unavailable. |
| Metadata and structured data | Metadata checks, preview checks, advisory output | Issue evidence only | Yes | Metadata is advisory unless project policy says otherwise. |
| Computed styles and measurements | Contrast, visibility, reflow, diagnostics | Issue evidence only | Yes | Complex paint composition can force review. |
| Runtime diagnostics | Permissions, frames, storage, errors, limitations | Diagnostic state/history where applicable | Yes | Diagnostic signals are not page defects by themselves. |
Privacy note
Extracted information is processed locally in the documented local-first workflow. Exported files may include URLs, selectors, snippets, issue evidence, screenshots where captured, diagnostics, and notes. Treat exports as sensitive.