WCAG Standards for Visual Impairments

Full Standards: WCAG 2.1

Simple Standards: WCAG for people who haven't read them

Introduction to the Principles

from WebAIM

  1. Perceivable: Web content is made available to the senses - sight, hearing, and/or touch
  2. Operable: Interface forms, controls, and navigation are operable.
  3. Understandable: Information and the operation of user interface must be understandable.
  4. Robust: Content must be robust enough that it can be interpreted by a wide variety of user agents, including assistive technologies

Synopsis of Standards

from PSU

Principle 1: Perceivable

  • Guideline 1.1: Text Equivalent

    "Provide text alternatives for any non-text content so that it can be changed into other forms people need, such as large print, braille, speech, symbols or simpler language."
  • Guideline 1.2: Time Based Media (Audio/Video)

    "Provide alternatives for time-based media."
  • Guideline 1.3: Adaptable

    "Create content that can be presented in different ways (for example simpler layout) without losing information or structure."
  • Guideline 1.4: Distinguishable

    "Make it easier for users to see and hear content including separating foreground from background."

Principle 2: Operable

  • Guideline 2.1: Keyboard Accessible

    "Make all functionality available from a keyboard."
  • Guideline 2.2: Enough Time

    "Provide users enough time to read and use content."
  • Guideline 2.3: Seizures

    "Do not design content in a way that is known to cause seizures."
  • Guideline 2.4: Navigable

    "Provide ways to help users navigate, find content, and determine where they are."

Principle 3: Understandable

  • Guideline 3.1: Readable

    "Make text content readable and understandable."
  • Guideline 3.2: Predictable

    "Make Web pages appear and operate in predictable ways."
  • Guideline 3.3: Input Assistance

    "Help users avoid and correct mistakes."

Principle 4: Robust

  • Guideline 4.1: Compatible

    “Maximize compatibility with current and future user agents, including assistive technologies.”