PopStateEvent: hasUAVisualTransition property

Baseline 2026

Newly available

Since March 2026, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

The hasUAVisualTransition read-only property of the PopStateEvent interface returns true if the user agent performed a visual transition for this navigation before dispatching this event, or false otherwise.

User agents may provide a built-in visual transition when executing site navigations. If the site author also adds a visual transition, user agent and author transitions may conflict and confuse a visitor. The property lets you detect whether a UA transition was provided so that you can skip author transitions for a better user experience.

Value

A boolean value.

Examples

window.addEventListener("popstate", async (event) => {
  // Fetch the new content
  const newContent = await fetchNewContent(location.href);

  // The UA does not support View Transitions, or the UA
  // already provided a Visual Transition by itself (e.g. swipe back).
  // In either case, update the DOM directly
  if (!document.startViewTransition || event.hasUAVisualTransition) {
    doSinglePageAppNav(newContent);
    return;
  }

  // Update the content using a View Transition
  document.startViewTransition(() => {
    doSinglePageAppNav(newContent);
  });
});