JAVASCRIPT

javascript fadein fadeout

#slideSource {
  opacity: 1;
  transition: opacity 1s; 
}

#slideSource.fade {
  opacity: 0;
}

javascript fadein fadeout

var slideSource = document.getElementById('slideSource');

document.getElementById('handle').onclick = function () {
  slideSource.classList.toggle('fade');
}

js fadeout

const target = document.getElementById("target");

target.addEventListener('click', () => target.style.opacity = '0');
// If you want to remove it from the page after the fadeout
target.addEventListener('transitionend', () => target.remove());

javascript fadein fadeout

<button id="handle">Fade</button> 
<div id="slideSource">Whatever you want here - images or text</div>
 Run code snippet