Avoid implementing website features that trigger unpredictable events (i.e., events that cause a change of focus or context) when a user hovers over or tabs to an element.
For an overview of this issue, see Predictability in our IT Accessibility Checklist.
Techniques
Avoid using features that trigger a change in focus or context on hover or focus. For example:
- Opening a new window
- Moving focus to a different component
- Going to a new page
- Significantly re-arranging the content of the page
A change in focus or context should happen only at the user’s request. Users should be informed of what to expect prior to taking action, then if they choose to take that action, they can do so with a mouse click or key press.