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

Success Criterion 1.4.9 Images of Text (No Exception) (Level AAA): 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

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

Examples

Related Resources

Resources are for information purposes only, no endorsement implied.

Techniques

Each numbered item in this section represents a technique or combination of techniques that the WCAG Working Group deems sufficient for meeting this Success Criterion. However, it is not necessary to use these particular techniques. For information on using other techniques, see Understanding Techniques for WCAG Success Criteria, particularly the "Other Techniques" section.

Sufficient Techniques

  1. C22: Using CSS to control visual presentation of text
  2. SL31: Using Silverlight Font Properties to Control Text Presentation
  3. C30: Using CSS to replace text with images of text and providing user interface controls to switch
  4. G140: Separating information and structure from presentation to enable different presentations
  5. PDF7: Performing OCR on a scanned PDF document to provide actual text

Advisory Techniques

Although not required for conformance, the following additional techniques should be considered in order to make content more accessible. Not all techniques can be used or would be effective in all situations.

Failures

The following are common mistakes that are considered failures of this Success Criterion by the WCAG Working Group.

Key Terms

essential

if removed, would fundamentally change the information or functionality of the content, and information and functionality cannot be achieved in another way that would conform

pure decoration

serving only an aesthetic purpose, providing no information, and having no functionality

Note

Text is only purely decorative if the words can be rearranged or substituted without changing their purpose.

The cover page of a dictionary has random words in very light text in the background.

text

sequence of characters that can be programmatically determined, where the sequence is expressing something in human language