TransitionClassestype

{
	default: string;
	forward?: string;
	back?: string;
}
PropertyType
.defaultstring
required
.forwardstring
.backstring

Map of view-transition types to their CSS class names in { type: className } format.

  • Each key is a "transition type" set with the React addTransitionType() API inside a startTransition() callback, e.g. "forward".
  • Each value is a "transition class" that React sets on the element as its view-transition-class: forward; CSS property — should correspond to a ::view-transition-old(.slideForward) rule.