Understanding Success Criterion 1.4.9: Images of Text (No Exception)

Images of text are only used for pure decoration or where a particular presentation of text is essential to the information being conveyed.

Logotypes (text that is part of a logo or brand name) are considered essential.

Intent of Success Criterion 1.4.9: Images of Text (No Exception)

The intent of this Success Criterion is to enable people who require a particular visual presentation of text to be able to adjust the text presentation as required. This includes people who require the text in a particular font size, foreground and background color, font family, line spacing or alignment.

This means implementing the text in a manner that allows its presentation to be changed or providing a mechanism by which users can select an alternate presentation. Using images of text is an example of an implementation that does not allow users to alter the presentation of the text within it.

In some situations, a particular visual presentation of the text is essential to the information being conveyed. This means that information would be lost without that particular visual presentation. In this case implementing the text in a manner that allows its presentation to be changed is not required. This includes text that demonstrates a particular visual aspect of the text, such as a particular font family, or text that conveys an identity, such as text within a company logo.

Text that is decorative does not require implementing the text in a manner that allows its presentation to be changed.

The definition of image of text contains the note: Note: This does not include text that is part of a picture that contains significant other visual content. Examples of such pictures include graphs, screenshots, and diagrams which visually convey important information through more than just text.

Benefits of Success Criterion 1.4.9: Images of Text (No Exception)

Examples of Success Criterion 1.4.9: Images of Text (No Exception)

Resources Success Criterion 1.4.9: Images of Text (No Exception)

Techniques for Success Criterion 1.4.9: Images of Text (No Exception)

Sufficient Techniques

  1. Using CSS to control visual presentation of text
  2. SL31
  3. Using CSS to replace text with images of text and providing user interface controls to switch
  4. Separating information and structure from presentation so that Web pages can be presented different ways without losing information
  5. PDF7

Advisory Techniques

  • Using server-side scripts to resize images of text (future link)

Failures