An accessibility layer is a technical category describing where and how an accessibility intervention operates, specifically, at the runtime layer of a web page, after the page has been rendered by the browser. Understanding the layer matters because it determines what a tool can and cannot do — and because most well-built accessibility programs combine more than one layer rather than relying on a single one.

How an accessibility layer works

An accessibility layer works by fixing things on the page after it’s already loaded in the browser — not by changing the code that lives on the server. So instead of editing a file and re-publishing the page, it steps in once the page is already built and adjusts it live, in front of the user.

It can do this because of how browsers work. When a page loads, the browser builds something called the Document Object Model (DOM) — its own live, editable copy of the page — and that’s what the accessibility layer actually touches: fixing contrast, adding Accessible Rich Internet Applications (ARIA) attributes, labeling form fields, fixing keyboard focus, all directly on that live copy.

The tradeoff is that these fixes only exist while the layer is active. Turn it off, and the original code — unfixed — is all that’s left, so the same barriers come back. That’s the reason a solid accessibility program doesn’t stop at this layer: it also fixes the underlying code, and brings in human judgment for what no automated layer can catch on its own.

What accessibility layers address

An accessibility layer is good at catching problems a computer can check on its own: color contrast that’s too low to read easily, images missing a text description, form fields with no label, missing markup that tells a screen reader what a section is, buttons and links that can’t be reached by keyboard, and headings that are out of order.

What it can’t do is judge things that need a human eye: whether an image’s description actually makes sense in context, whether a screen reader user could really complete a task on the page, or whether paperwork meets a particular standard. Those need a person to fix, not a runtime layer.

accessiBe’s three layers

accessiBe’s platform is built around three layers working together, not any single one carrying the full weight:

  • Layer 1 — accessWidget: The runtime layer described above. It includes AI-powered background remediation, which scans the page and applies corrections, and an accessibility interface, which gives users manual controls of their own.
  • Layer 2 — accessFlow: Works at the source-code level, auditing a site against WCAG, prioritizing what developers need to fix, and tracking that work through resolution — the layer a runtime tool can’t reach.
  • Layer 3 — accessServices: Human expertise applied to what neither automation nor source-code tooling can judge on its own: manual audits, VPATs, accessibility statements, and user testing with people with disabilities.