Certain CSS declarations display text or images that are invisible to user agents not supporting or rendering stylesheets. For example, if CSS is disabled, a background-image will not be visible, whereas an HTML element would remain accessible.

Objectives

• Ensure access to information integrated via CSS (such as background images) in environments where styles are not rendered, such as screen readers or browsers with CSS disabled.
• Improve overall content accessibility for users with disabilities.

Implementation

• Provide a text equivalent for any essential content displayed only through CSS. This includes information conveyed by background images, content added via pseudo-elements (::before or ::after), or any visual effect that disappears when styles are deactivated.

Control

• Check for the use of CSS pseudo-elements (::before, ::after) and background-image properties.
• Visually compare the standard display of the page with its rendering when background images are disabled.
• Compare the content display with and without stylesheets to ensure all information remains available.