Answers for "zoomin zoomout animation in javascript"

css animation zoom in-out infinite

.examplediv {
  height: 500px;
  width: 500px;
  animation: zoom-in-zoom-out 5s ease-in infinite;
}

@keyframes zoom-in-zoom-out {
0% {
transform: scale(1, 1);
}
50% {
transform: scale(1.5, 1.5);
}
100% {
transform: scale(1, 1);
}
}

zoom out browser javascript

/* via css */

body {
   -moz-transform: scale(0.8, 0.8);
   zoom: 0.8;
   zoom: 80%;
}