1.4.8: Visual Presentation [AAA]
Description
For the visual presentation of blocks of text, a mechanism is available to achieve the following:
- Foreground and background colors can be selected by the user.
- Width is no more than 80 characters or glyphs (40 if CJK).
- Text is not justified (aligned to both the left and the right margins).
- Line spacing (leading) is at least space-and-a-half within paragraphs, and paragraph spacing is at least 1.5 times larger than the line spacing.
- Text can be resized without assistive technology up to 200 percent in a way that does not require the user to scroll horizontally to read a line of text on a full-screen window.
Content is not required to use these values. The requirement is that a mechanism is available for users to change these presentation aspects. The mechanism can be provided by the browser or other user agent. Content is not required to provide the mechanism.
Writing systems for some languages use different presentation aspects to improve readability and legibility. If a presentation aspect in this success criterion is not used in a writing system, content in that writing system does not need to use that presentation setting and can conform without it. Authors are encouraged to follow guidance for improving readability and legibility of text in their writing system.
Sufficient Techniques
Sufficient Techniques for Success Criterion 1.4.8
Note: Other techniques may also be sufficient if they meet the success criterion. See Understanding Techniques.
First Requirement: Techniques to ensure foreground and background colors can be selected by the user
- C23: Specifying text and background colors of secondary content such as banners, features and navigation in CSS while not specifying text and background colors of the main content OR
- C25: Specifying borders and layout in CSS to delineate areas of a Web page while not specifying text and text-background colors OR
- G156: Using a technology that has commonly-available user agents that can change the foreground and background of blocks of text OR
- G148: Not specifying background color, not specifying text color, and not using technology features that change those defaults OR
- G175: Providing a multi color selection tool on the page for foreground and background colors OR
Second Requirement: Techniques to ensure width is no more than 80 characters or glyphs (40 if CJK)
Third Requirement: Techniques to ensure text is not justified (aligned to both the left and the right margins)
Fourth Requirement: Techniques to ensure line spacing (leading) is at least space-and-a-half within paragraphs, and paragraph spacing is at least 1.5 times larger than the line spacing
Fifth Requirement: Techniques to ensure text can be resized without assistive technology up to 200 percent in a way that does not require the user to scroll horizontally to read a line of text on a full-screen window
- Not interfering with the user agent's reflow of text as the viewing window is narrowed
- G146: Using liquid layout AND using measurements that are relative to other measurements in the content by
- G206: Providing options within the content to switch to a layout that does not require the user to scroll horizontally to read a line of text