Text size and font

The sizes and fonts utilized on a site can have a tremendous effect on the readability of various titles, links, captions, paragraphs, etc. While diversity of fonts and sizes is certainly permissible, there are certain precautions that should be taken to ensure written content is always legible and otherwise capable of being read, including:

• Use of non-/sans-serif fonts. These are fonts that do not have “serifs,” or small projections at the ends of letters. Examples of non-serif fonts are Arial, Tahoma, Veranda and Helvetica.
• Ensure that font sizes can be increased or decreased. Provide users with instructions regarding how to do this via both a mouse and keystrokes.
• Additionally, consider adding a clickable option that allows users to manually click on and change text size.

Image descriptions

Image descriptions are not to be confused with image captions. Captions provide brief accompanying explanations about or information related to such items as images, videos, and articles. Image descriptions, as their name implies, provide full descriptions of images and the messages they are supposed to convey.

Appropriate image descriptions are necessary to ensure the accessibility of a website. Individuals who are blind or have low vision may not be able to see images that are necessary to convey a message on a website. Instead, they may be reliant on screen reading technology to provide them with audible readings of all content on the site, including image descriptions.

Two types of image descriptions are “alternative text” and “longdesc.”  Alternative text is used to provide a quick, effective message about an image; specifically, it should include a description of the image and an explanation of the message the image is meant to convey.  Longdesc is a type of longer description. Where a picture may be summed up in a few words or sentences of alternative text, more dense images like data tables, charts, and graphs may require more lengthy descriptions. For these longer descriptions, longdesc should be employed.

Alternative text for image descriptions is only used where the information provided is relevant to the user. Images used solely for decorative purposes or visual appeal, such as certain logos, graphics, and clip art, need not be described, as such information is not useful to the site user.  Instead, use the null-alt tab, or alt=””, which will tell screen readers to ignore that image.