NavigateEvent: hasUAVisualTransition property

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The hasUAVisualTransition read-only property of the NavigateEvent 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

js
navigation.addEventListener("navigate", (event) => {
  // Some navigations, e.g. cross-origin navigations, we
  // cannot intercept. Let the browser handle those normally.
  if (!event.canIntercept) {
    return;
  }

  // Don't intercept fragment navigations or downloads.
  if (event.hashChange || event.downloadRequest !== null) {
    return;
  }

  event.intercept({
    handler() {
      // Fetch the new content
      const newContent = await fetchNewContent(event.destination.url, {
        signal: event.signal,
      });

      // 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);
      });
    },
  });
});

Specifications

Specification
HTML
# dom-navigateevent-hasuavisualtransition

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
hasUAVisualTransition
Experimental

Legend

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Full support
Full support
No support
No support
Experimental. Expect behavior to change in the future.

See also