Код HTML

<div class="preloader">
    <div class="loader"></div>
</div> 

Код CSS

.preloader {
    background: #fff;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1000;
}
.loader {
    display: block;
    position: relative;
    left: 50%;
    top: 50%;
    width: 150px;
    height: 150px;
    margin: -75px 0 0 -75px;
    border-radius: 50%;
    border: 3px solid transparent;
    border-top-color: #3498db;
    animation: spin 2s linear infinite;
}
  
.loader:before {
    content: "";
    position: absolute;
    top: 5px;
    left: 5px;
    right: 5px;
    bottom: 5px;
    border-radius: 50%;
    border: 3px solid transparent;
    border-top-color: #e74c3c;
    animation: spin 3s linear infinite;
}
  
.loader:after {
    content: "";
    position: absolute;
    top: 15px;
    left: 15px;
    right: 15px;
    bottom: 15px;
    border-radius: 50%;
    border: 3px solid transparent;
    border-top-color: #f9c922;
    animation: spin 1.5s linear infinite;
}
  
@-webkit-keyframes spin {
    0%   {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}
@keyframes spin {
    0%   {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}

Код JavaScript

$(window).on('load', function() {
  $('.loader').delay(1000).fadeOut();
  $('.preloader').delay(1000).fadeOut('slow');
})