GIFs should not cause movement |
WAI / WCAG 1.0 Priority 2 checkpoint 7.3
Issue Description The page contains images that might have moving content. If this is the case, it is best to modify or remove them.
How to check Check if the image has moving content that does not stop and that cannot be stopped by the website visitor. If so, modify the image so that no movement occurs, or so that the movement occurs only a couple of times and then comes to rest.
Issue Explanation The image has moving content, and the user of the browser will in no way be able to stop this behavior. This behavior is very distracting to the eye, and will make it very difficult to concentrate on the task of reading the information in the page or filling in the form contained in the page.

The consequences will be even more significant on users that suffer from cognitive disorders, as they will have a very hard time concentrating on the page content. Consider also users of screen magnifiers who may read a small portion of the page that overlaps with the moving part. In these cases, a large part of the magnified screen will display a portion of the content that will move out of sight or change. The user will need to continuously reposition the screen magnifier by tracking the moving content, making it extremely hard for these users to concentrate on the task at hand.

Consider that, in a sense, everyone is cognitively disabled when under stress. For example, when buying an e-ticket for a flight from a kiosk in a very noisy and crowded airport, with a long line of people waiting for the same kiosk, most people will be unable to fully concentrate on the task. A moving element in the page will not help the user to complete the purchase.