Text
People with low vision use browser zoom tools and assistive technology such as ZoomText to increase the size of content on the screen. This exercise shows you the difference between zooming all the content versus zooming just the text on the page.
Text size​
For people with low vision, it is important to support the ability to increase text size without text overlapping or getting truncated. To test, use your browser's built-in zoom or text-resize feature to zoom and make sure text is still readable. If you are building for the mobile web, please don't disable pinch and zoom.
WCAG guidelines recommend allowing zooming up to 200% without loss of content.
More on fonts and accessibility in the WebAIM site.
For the exercise below, you will need a browser like Safari that allows you to increase just the text size instead of zooming in the whole page. On Safari, go to View and Zoom Text Only and then select Zoom In from the same menu. You will notice that the words bleed outside the box below. Try fixing this example by specifying the width and height as relative units, such as ems. Set the height to 3em and width to 10em and verify your answers.