Zooming and scaling
This information is intended for web developers, providing a holistic process for performing an initial pass of evaluating your website for accessibility. This is not a substitute for performing a complete testing for a website or application.
People with low vision may use any of several methods to enlarge content. They may use a screen magnifier such as Windows Magnifier or Mac Zoom, increase the default font size in their browser, zoom their browser, or change the default text spacing on a website. Different strategies for enlarging content behave differently, and you need to verify that important content is not lost if any of them are being used.
Three methods of enlarging content need to be checked because they can affect the website design: font size, zooming, and text spacing.
Most browsers have a way to change the default minimum font size. How font size changes will differ depending on the browser. Checking font size in more than one browser is recommended.
- Change the font size:
- Chrome: Open Settings or Preferences and change the font size to Very large or Very small
- Firefox: Open Preferences, select Content in the side menu, and then in the "Fonts & Colors" section, select Advanced. In the pop-up box, change the "Minimum font size" to at least 24 point. Select OK
- Safari: Open Preferences. In the pop-up box, select Advanced. Check the checkbox for Never use font sizes smaller than and, in the drop-down box, select 24 point
- Internet Explorer: In the View menu, select Text size, then change the font size to Largest or Smallest
- Reload the page
- Look for any text that does not change size and any content that is obscured, lost, hidden, or otherwise problematic
- Change back to your preferred settings