fullPage.js by default hides the scrollbar making it impossible for events relying on the scroll event to work as expected.

To fix this all you have to do is enable the scrollbar on fullPage.js by using the option scrollBar:true. This way fullPage.js snap effect will still work and you'll be able to enjoy Wow.js animations.

If you still prefer to keep the scrollbar hidden, as the animation will be a bit smoother, you can use fullPage.js callbacks such as onLeave or afterLoad to add the necessary classes Wow.js requires to trigger the animation.

Here's an example:

afterLoad: function(origin, destination, direction){
    $(destination.item).find('.to-animate').addClass('animated fadeInLeftBig');
},

Or if you do not use jQuery:

afterLoad: function(origin, destination, direction){
     destination.item.querySelectorAll('.to-animate').forEach(function(item){
          item.classList.add('animated', 'fadeInLeftBig');
     });
},

You can find more about this topic on the Github issues forum as well as on Stackoverflow.

You might also find these articles relevant:

• Why my scroll based animations or events don't work?