Success Criterion 3.2.1: On Focus

Understanding Success Criterion: 

When any component receives focus, it does not initiate a change of context.

Accessibility Level: 
A
Intent of Success Criterion: 

The intent of this Success Criterion is to ensure that functionality is predictable as visitors navigate their way through a document. Any component that is able to trigger an event when it receives focus must not change the context. Examples of changing context when a component receives focus include, but are not limited to:

  • forms submitted automatically when a component receives focus;
  • new windows launched when a component receives focus;
  • focus is changed to another component when that component receives focus;

Focus may be moved to a control either via the keyboard (e.g. tabbing to a control) or the mouse (e.g. clicking on a text field). Moving the mouse over a control does not move the focus unless scripting implements this behavior. Note that for some types of controls, clicking on a control may also activate the control (e.g. button), which may, in turn, initiate a change in context.
Note: What is meant by "component" here is also sometimes called "user interface element" or "user interface component''.

Specific Benefits of Success Criterion: 
  • This Success Criterion helps people with visual disabilities, cognitive limitations, and motor impairments by reducing the chance that a change of context will occur unexpectedly.