[Skip navigation links]

Accessibility Checkpoint WCAG 2 1.4.4


Use relative rather than absolute units in CSS property values.


Absolute units are CM, MM, IN, PC and PT. When used with fonts PX is also considered an absolute unit, because it isn’t relative the user’s preferred font size. Low-vision users, and a lot of people over 50, increase the browser default font size to make text easier to read. Absolute units ignore this user choice. Relative units like EM and percentages «stretch» according to the screen size and/or user’s preferred font size, and work on a large range of devices.

Applicable Standards

Note: Section 508 Refresh (2017) checkpoints are equivalent to WCAG 2.0 level AA checkpoints.

Change history

This page describes a web site issue detected by SortSite Desktop and OnDemand Suite.

Rule ID: AccWcag1-3.4.1