Techniques for WCAG 2.0

Skip to Content (Press Enter)


C13: Using named font sizes

Important Information about Techniques

See Understanding Techniques for WCAG Success Criteria for important information about the usage of these informative techniques and how they relate to the normative WCAG 2.0 success criteria. The Applicability section explains the scope of the technique, and the presence of techniques for a specific technology does not imply that the technology can be used in all situations to create content that meets WCAG 2.0.



This technique relates to:

User Agent and Assistive Technology Support Notes

See User Agent Support Notes for C13.


The objective of this technique is to specify a named font size that expresses the relative font size desired. These values provide hints so that the user agent can choose a font-size relative to the inherited font-size.


Example 1: Named font sizes in CSS

This example selects a larger font size for strong elements so that their text will always be larger than the surrounding text, in whatever context they are used. Assuming that headings and paragraphs use different font sizes, the emphasized words in this example will each be larger than their surrounding text.

Example Code:

strong {font-size: larger}


<h1>Letting the <strong>user</strong> control text size</h1>
<p>Since only the user can know what size text works for him, 
it is <strong>very</strong> important to let him configure the text size.  


Resources are for information purposes only, no endorsement implied.



  1. Check that the value of the CSS property that defines the font size is one of xx-small, xx-small, x-small, small, medium, large, x-large, xx-large, xsmaller, or larger.

Expected Results

If this is a sufficient technique for a success criterion, failing this test procedure does not necessarily mean that the success criterion has not been satisfied in some other way, only that this technique has not been successfully implemented and can not be used to claim conformance.