The info read-only property of the NavigateEvent interface returns the info data value passed by the initiating navigation operation (e.g. Navigation.back(), or Navigation.navigate()), or undefined if no info data was passed.

The info value passed by the initiating navigation operation, or undefined if none was passed.

One example of how info might be used is to trigger different single-page navigation renderings depending on how a certain route was reached. For example, consider a photo gallery app, where you can reach the same photo URL and state via various routes. You might want to use a different animation to show the photo for each route.

navigation.addEventListener("navigate", (event) => {
  if (isPhotoNavigation(event)) {
    event.intercept({ async handler() {
      switch (event.info.?via) {
        case "go-left": {
          await animateLeft();
          break;
        }
        case "go-right": {
          await animateRight();
          break;
        }
        case "gallery": {
          await animateZoomFromThumbnail(event.info.thumbnail);
          break;
        }
      }

      // TODO: actually load the photo.
    } });
  }
});

• Modern client-side routing: the Navigation API
• Navigation API explainer
• Domenic Denicola's Navigation API live demo
• Methods that allow info to be passed — Navigation.back(), Navigation.forward(), Navigation.navigate(), Navigation.reload(), and Navigation.traverseTo()