Images

Benefits: Blind disabilities.

All non-text content that is presented to the user has a text alternative that serves the equivalent purpose, except for the situations listed below:

• Controls, Input: If non-text content is a control or accepts user input, then it has a name that describes its purpose.
• Time-Based Media: If non-text content is time-based media, then text alternatives at least provide descriptive identification of the non-text content.
• Test: If non-text content is a test or exercise that would be invalid if presented in text, then text alternatives at least provide descriptive identification of the non-text content.
• Sensory: If non-text content is primarily intended to create a specific sensory experience, then text alternatives at least provide descriptive identification of the non-text content.
• CAPTCHA: If the purpose of non-text content is to confirm that content is being accessed by a person rather than a computer, then text alternatives that identify and describe the purpose of the non-text content are provided, and alternative forms of CAPTCHA using output modes for different types of sensory perception are provided to accommodate different disabilities.
• Decoration, Formatting, Invisible: If non-text content is pure decoration, is used only for visual formatting, or is not presented to users, then it is implemented in a way that it can be ignored by assistive technologies.

Images can be one of the following:

• Informative: Conveys a simple concept or information that can be expressed in a short phrase or sentence.
• Functional: Initiatse interactive actions.
• Decorative: Does not add information to the content of a page, and thus the image can have null/empty alt text. Assistive technologies can ignore the image. The image may have adjacent text that sufficiently describes the image.

Benefits: Low vision, visual tracking problems, cognitive disabilities.

Text is used to convey information rather than images of text. Achieve desired default visual presentation, to enable people who require a particular visual presentation of text to be able to adjust the text presentation as needed.