Use MathML for mathematical expressions

Rule ID Image 7
Definition Mathematical expressions must be marked up using MathML instead of bitmapped images.
Purpose
  • Images used to convey mathematical expressions are not accessible to people with disabilities using assistive technologies.
  • MathML is a W3C standard for representing mathematical expressions for web technologies and is the most accessible web math format for people using assistive technologies.
  • MathML has capabilities similar to SVG graphics, providing the abilities to resize and style content without the loss of fidelity of the visual rendering to match the capabilities of people with visual impairments.
Mappings
  • HTML4 Legacy Techniques (Required)
  • HTML5 and ARIA Techniques (Required)
WCAG Success Criteria

1.1.1 Non-text Content (Level A, Primary Success Criterion)

Rule Category Images
Scope Element
Target Resources img and [role="img"] elements representing mathematical expressions
  • img
Techniques
  • Use MathML to represent the mathematical expressions.
  • Use MathJax to support MathML rendering in a wide range of browsers with and without native support for rendering MathML.
  • Design Science MathPlayer is a universal math reader that now enables math to be spoken in many assistive technology products.
Informational Links