Web Accessibility at the University of California

Use relative font sizes

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The Challenge
People with low vision can improve the readability of a Web page for themselves by increasing the font size. They do this using the browser's text-size preference settings. If a fixed font size has been specified, though, the user cannot exercise this control.

Solutions

• Use relative sizing: percentages (%) or ems (em).
• Avoid absolute sizing: points (pt) or pixels (px)

Additional Information

• WebAIM article on relative fonts
• W3C techniques for units of measure