All images on a web page should be related to and enhance the content. The addition of alternative text or "alt" text gives a user who is blind or visually impaired access to information about an image.
Accessible images allow users who use assistive technologies equal access to information provided by an image.
Best Practices for Accessible Images
- Add images if they are relevant to the content on the webpage.
- The insertion point within a webpage where an image can be added should reside before or after a full sentence, not in the middle.
- Do not place images in headings.
- Write, concise, descriptive phrases or sentences for the alt text.
- For example, "image28356" or "picture" will never be helpful alt text; however, "students meeting to plan Dillo Day" could be good alt text for a picture on the Office of Student Engagement web site.
- Images should add to the content but should not be the content.
- For example, don't use an image of a flyer in place of stating the flyer's essential information on the page.
- Images with instructional text should include similar information in the alt text.
- Provide text in an alternate accessible format if necessary. For example, if you wish to use an infographic, create an accessible word document that describes the infographic and link to it from above the image.
- Images used as buttons to forms (e.g., "submit") should indicate in the alt text that they are forms.