When a user interface component receives keyboard focus, the component and its focus indicator may not be completely hidden or cut off.
What you need to know
- Among other users, people with ADHD or cognitive disabilities can benefit from always having the focus indicator visible to them.
- A focused element that’s hidden behind other page content is obviously not accessible.
- In the case of movable content such as toolbars or non-modals, if the user can move the position of the elements, only the initial position is considered for testing and conformance to this success criterion.
What you need to do
- Examples of content that may overlap focused items include sticky footers—those that are attached to the bottom of the viewing area. Make sure that when a user is tabbing through a webpage an item in focus isn’t hidden because the header or footer overlaps it.
- Even though a component that a user is focusing on might be partially hidden, you must make sure that it’s still mainly visible.
Reference
Read the full explanation of success criterion 2.4.12 on W3.org.