Purchase College principles for creating alternative text include:

  • Focus on the purpose for the inclusion of the visual information in the text.
  • Write concise descriptions that move from general info to specifics.
  • Consider context and objectivity when determining what to write.
  • Always consider your audience in tone and language.

Alternative Text Rules

  • Every image must have an alt attribute.
  • Alternative text should:
    • present the CONTENT and FUNCTION of the image.
    • be succinct.
  • Alternative text should not:
    • be redundant (be the same as adjacent or body text).
    • use the phrases “image of…” or “graphic of…”.
  • Appropriate alternative text depends heavily on the image’s context.
  • Alt text of a functional image (e.g., an image within a link) should describe the function as well as the content.

The accessibility of the web in general would increase dramatically if alternative text were provided and implemented correctly.

Read more about alternative text at WebAIMCopyright © 1999-2017 WebAIM (Web Accessibility in Mind). All rights reserved. Copyright & Terms of Use

Meaningful Text Alternatives for Images

For each image, you must include meaningful alternative text that provides equivalent content. For example, an “event poster” where the image provides the date, time, description and location of the event, you must provide that same content as “alternative text.” For images that are used for aesthetics only, the Alt-Text should say just that – i.e. “no image content - decorative image only.”

The purpose of text alternatives for images is to ensure that information conveyed through images is also accessible through the use of an alternative format (text.)

Alternative Text for visual images helps in many different ways. Those who have a hard time perceiving visual content will be able to hear the content when it is read aloud with assistive technology. Those with a hearing impairment will be able to read the text. Text alternatives also help those who have a hard time understanding the meaning of drawings, graphs, or photographs. Text alternatives may also improve the ability to search for and locate content that is not text.

Avoid Text in Images

You should avoid using images with text in images. Screen readers cannot text in an image. If there is enough text it will be too much to put in as alternative text, with a 125 character limit on most screen readers. In these situations you must represent the text in the rest of your content using paragraphs and headers as normal. You are now representing the information twice on a page, which does not look good to most visual users, and can be confusing for people with cognitive disabilities.

Use Proper Color Contrast in Images

The example below fails to provide critical equivalents for visual content such as the location of the store and non-standard operating hours. It also runs afoul of contrast requirements for color blindness (please visit the color contrast page)

Poor use of contrast and text in an image