Mermaid.js Accessibility Guide: Making Diagrams Screen-Reader Friendly

# Mermaid.js Accessibility Guide: Making Diagrams Screen-Reader Friendly

Mermaid.js is the de facto standard for text-to-diagram rendering in developer docs. But out of the box, rendered SVG diagrams are invisible to screen readers. Every , , and element sits in the DOM without any semantic meaning.

If your docs live on a public site, an internal wiki, or a product help center, inaccessible diagrams mean you are shutting out users who rely on assistive technology — and potentially violating WCAG 2.1 requirements.

This guide covers every technique available in Mermaid 10+ to make diagrams accessible: ARIA attributes, descriptive text, accessible color palettes, and integration patterns for common platforms.

The Problem: Mermaid SVG Is Not Accessible by Default

A Mermaid flowchart rendered from this source:

graph TD
    A[Login] --> B{Dashboard}
    B -->|Admin| C[Admin Panel]
    B -->|User| D[User Profile]

Produces SVG output that a screen reader encounters as an opaque blob of vector paths. There are no landmark roles, no heading structure, no text alternatives. The user hears nothing useful.

Solution 1: The `accessibility` Config (Mermaid 10.3+)

Mermaid 10.3 introduced a dedicated accessibility configuration object. This is the most important feature for diagram accessibility:

mermaid.initialize({
  accessibility: {
    title: "User Authentication Flow",
    description: "Flowchart showing login redirecting to Admin Panel or User Profile based on role",
    svgRole: "img"
  }
});

What Each Setting Does