New Web Semantics API proposal would expose accessibility metadata to web components

Tech · 6 min read

A consortium of browser vendors and accessibility experts published a draft Web Semantics API that lets web components expose high-level accessibility intent—such as 'status', 'authoritative label', or 'interactive group'—alongside ARIA attributes. The goal is to reduce mismatch between component internals and the semantics announced to assistive technologies.

Prototypes demonstrate that assistive tech can use the semantic layer to create more accurate linearization and change announcements for complex widgets like virtualized lists and custom controls. The API also includes an opt-in discovery endpoint so automated tools can query component capabilities and run targeted tests without relying solely on DOM heuristics.

Security and privacy reviewers in the working group have proposed throttles and permission models for certain metadata to avoid fingerprinting. Polyfills are already available for older browsers, and several popular component libraries are experimenting with the API to reduce ARIA duplication and simplify design system documentation.