files/en-us/web/api/document/activeviewtransition/index.md
{{APIRef("DOM")}}
The activeViewTransition read-only property of the {{domxref("Document")}} interface returns a {{domxref("ViewTransition")}} instance representing the view transition currently active on the document.
The current {{domxref("ViewTransition")}} can be accessed in other ways:
viewTransition property of the {{domxref("Window.pagereveal_event", "pagereveal")}} and {{domxref("Window.pageswap_event", "pageswap")}} event objects in the case of cross-document view transitions.However, the activeViewTransition property provides a consistent way to access the active view transition in any context, without having to worry about saving it for easy access later on.
A {{domxref("ViewTransition")}} or null if there is no active view transition.
// Start a view transition
document.startViewTransition(() => {
// Update the UI to reflect the new state
updateUI();
});
// Check if a view transition is currently active
if (document.activeViewTransition) {
console.log("A view transition is currently active");
}
// Respond to view transition finishing
document.activeViewTransition.finished.then(() => {
console.log("View transition finished");
});
{{Specifications}}
{{Compat}}