This spec has been deprecated, please see the Accessibility Object Model Explainer and index to specs for up to date information.


This document is the spec for Phase 4 of the Accessibility Object Model spec. For background, please refer to the Accessibility Object Model Explainer for the background and motivation, and then Phase 1, Phase 2, and Phase 3.

Phase 4: Computed Accessibility Tree

The Computed Accessibility Tree API will allow authors to access the full computed accessibility tree - all computed properties for the accessibility node associated with each DOM node, plus the ability to walk the computed tree structure including virtual nodes.

This will make it possible to:

One implication of implementing this phase is that all browsers must agree on exposing the *same* accessibility tree for the same given webpage, otherwise differences will invariably lead to authored pages that work in some browsers but not others. Care must be taken to define this phase in such a way that maintains a high degree of compatibility between browsers, without exposing any internal details and nuances.