3.2.2 On Input
TL;DR: Changing a setting or entering input must not automatically cause a major context change without warning (like navigating away or submitting). Users need control and predictability.
Official description of the success criterion
Changing the setting of any user interface component does not automatically cause a change of context unless the user has been advised of the behavior before using the component.
What to do?
Ensure changes of context are initiated only on user request.
Why is it important?
Helps users maintain control over their interactions.
Common pitfalls
WCAG Failure F36: Automatically submitting a form and presenting new content without prior warning when the last field in the form is given a value.
WCAG Failure F37: Launching a new window without prior warning when the selection of a radio button, check box or select list is changed.