Accessibility Principles & Best Practices

Accessibility principles and best practices

Accessibility is not about disability; it is about ability. It is about making it easier for everyone to:

  • Acquire the same information
  • Engage in the same interactions
  • Enjoy the same services

All of this should happen in an equally effective and equally integrated manner, with substantially equivalent ease of use for people with and without disabilities.

Principles for Information and Communication Technology (ICT)

The CSU Accessible Technology Initiative (ATI) applies four core principles to information and communication technology (ICT). These align with the Web Content Accessibility Guidelines (WCAG) 2.1: Perceivable, Operable, Understandable, Robust (often shortened to “POUR”).

  1. Perceivable – Individuals can perceive the information being presented. Examples include text alternatives for images, captions for video, and sufficient color contrast.
  2. Operable – Users can navigate and operate the interface using different input methods (not just a mouse), such as keyboard or assistive technology.
  3. Understandable – Content and operation are clear and predictable so that people with different learning styles and abilities can use them.
  4. Robust – Content and tools work reliably with a wide range of current and future user agents, including assistive technologies.

Universal Design principles

Universal Design is about creating environments, products, and communications that work well for the widest possible range of people from the start. The principles below apply to both physical and digital spaces.

  • Equitable Use – The design is useful and marketable to people with diverse abilities.
  • Flexibility in Use – The design accommodates a wide range of individual preferences and abilities.
  • Simple and Intuitive – Use of the design is easy to understand, regardless of the user’s experience, knowledge, language skills, or current concentration level.
  • Perceptible Information – The design communicates necessary information effectively to the user, regardless of ambient conditions or the user’s sensory abilities.
  • Tolerance for Error – The design minimizes hazards and the adverse consequences of accidental or unintended actions.
  • Low Physical Effort – The design can be used efficiently and comfortably and with a minimum of fatigue.
  • Size and Space for Approach and Use – Appropriate size and space are provided for approach, reach, manipulation, and use regardless of body size, posture, or mobility.

Best practices for accessibility

The practices below bring together key requirements from WCAG 2.1 and universal design to make your web pages, documents, and applications more accessible and usable for everyone.

Organized content

Organized content makes pages easier to scan and understand for everyone.

  • Use headings and subheadings in a logical sequence to group related information.
  • Break long blocks of text into shorter paragraphs and lists.
  • Use images, tables, and other media only when they support the main message.
  • Ensure that the reading order matches the visual order of the page.

Alternative or alt text

Alternative text (alt text) communicates the purpose or meaning of images to people who cannot see them or who use assistive technologies.

  • Provide meaningful alt text for images that convey important information.
  • Use alt="" for purely decorative images so screen readers skip them.
  • Describe the purpose of the image, not every visual detail.
  • Avoid repeating text that is already provided in nearby captions or headings.

For more guidance, see the Alternate Text page.

Color

Color should support content, not be the only way information is communicated.

  • Do not rely on color alone to indicate required fields, status, or categories.
  • Ensure sufficient contrast between text and background (at least 4.5:1 for normal text).
  • Check color contrast using a contrast checker before publishing.
  • Use patterns, labels, or shapes in addition to color in charts and graphs.

For more details, see the Color and Styling page.

Keyboard navigation or touch

All interactive content must be usable with different input methods, including keyboard, mouse, and touch.

  • Users should be able to reach and operate all interactive elements (links, buttons, forms, menus) using only the keyboard.
  • Provide a visible focus indicator so users can see where they are on the page.
  • Ensure that menus, accordions, and other widgets work with both keyboard and pointer input.
  • Design layouts that work on different screen sizes (phone, tablet, laptop, desktop) without hiding important content.

See Keyboard Accessibility for more details.

Descriptive hyperlinks

Link text should clearly describe the destination or action.

  • Avoid vague phrases such as “Read more,” “Click here,” or “Continue” when used alone.
  • Write link text that makes sense out of context (for example, “Web Accessibility at AVÀÇ”).
  • Describe the destination (for example, document name, page title, or website).
  • Use unique link text for links that go to different destinations.
  • Do not rely on color alone to identify links; use underlines or other visual cues.

How to evaluate accessibility based on four principles

These quick checks align with WCAG 2.1 principles and can help identify common accessibility barriers before publishing.

  1. Font: Is the font styling easy to read (size, weight, and spacing)?
  2. Color: Is there enough contrast between text and background to be easily read by people with low vision or color vision differences?
  3. Tab: Can a user navigate through all interactive elements using only the keyboard (Tab, Shift+Tab, Enter, Space, arrow keys)?
  4. Enlarge: Can a user increase the text size (for example, Ctrl + or browser zoom) up to 200% without losing content or functionality?

Last updated: December 2025