Snippet Bootstrap 4 Multi-Card Carousel Without Plugin

Requirements

name url
bootstrap css https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0/css/bootstrap.css
jquery js https://code.jquery.com/jquery-1.12.4.min.js
bootstrap js https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0/js/bootstrap.min.js

Using jQuery for supporting older browser

HTML

<div class="container-fluid">
  <h1 class="text-center mb-3">Bootstrap 4 Multi-Card Carousel Without Plugin</h1>
  <div id="myCarousel" class="carousel slide" data-ride="carousel">
    <div class="carousel-inner row w-100 mx-auto">
      <div class="carousel-item col-md-4 active">
        <div class="card">
          <img class="card-img-top img-fluid" src="https://via.placeholder.com/800x600/f44242/fff" alt="Card image cap">
          <div class="card-body">
            <h4 class="card-title">Card 1</h4>
            <p class="card-text">This is a longer card with supporting text below as a natural lead-in to additional
              content. This content is a little bit longer.</p>
            <p class="card-text"><small class="text-muted">Last updated 3 mins ago</small></p>
          </div>
        </div>
      </div>
      <div class="carousel-item col-md-4">
        <div class="card">
          <img class="card-img-top img-fluid" src="https://via.placeholder.com/800x600/418cf4/fff" alt="Card image cap">
          <div class="card-body">
            <h4 class="card-title">Card 2</h4>
            <p class="card-text">This is a longer card with supporting text below as a natural lead-in to additional
              content. This content is a little bit longer.</p>
            <p class="card-text"><small class="text-muted">Last updated 3 mins ago</small></p>
          </div>
        </div>
      </div>
      <div class="carousel-item col-md-4">
        <div class="card">
          <img class="card-img-top img-fluid" src="https://via.placeholder.com/800x600/3ed846/fff" alt="Card image cap">
          <div class="card-body">
            <h4 class="card-title">Card 3</h4>
            <p class="card-text">This is a longer card with supporting text below as a natural lead-in to additional
              content. This content is a little bit longer.</p>
            <p class="card-text"><small class="text-muted">Last updated 3 mins ago</small></p>
          </div>
        </div>
      </div>
      <div class="carousel-item col-md-4">
        <div class="card">
          <img class="card-img-top img-fluid" src="https://placehold.it/800x600/42ebf4/fff" alt="Card image cap">
          <div class="card-body">
            <h4 class="card-title">Card 4</h4>
            <p class="card-text">This is a longer card with supporting text below as a natural lead-in to additional
              content. This content is a little bit longer.</p>
            <p class="card-text"><small class="text-muted">Last updated 3 mins ago</small></p>
          </div>
        </div>
      </div>
      <div class="carousel-item col-md-4">
        <div class="card">
          <img class="card-img-top img-fluid" src="https://via.placeholder.com/800x600/f49b41/fff" alt="Card image cap">
          <div class="card-body">
            <h4 class="card-title">Card 5</h4>
            <p class="card-text">This is a longer card with supporting text below as a natural lead-in to additional
              content. This content is a little bit longer.</p>
            <p class="card-text"><small class="text-muted">Last updated 3 mins ago</small></p>
          </div>
        </div>
      </div>
      <div class="carousel-item col-md-4">
        <div class="card">
          <img class="card-img-top img-fluid" src="https://via.placeholder.com/800x600/f4f141/fff" alt="Card image cap">
          <div class="card-body">
            <h4 class="card-title">Card 6</h4>
            <p class="card-text">This is a longer card with supporting text below as a natural lead-in to additional
              content. This content is a little bit longer.</p>
            <p class="card-text"><small class="text-muted">Last updated 3 mins ago</small></p>
          </div>
        </div>
      </div>
      <div class="carousel-item col-md-4">
        <div class="card">
          <img class="card-img-top img-fluid" src="https://via.placeholder.com/800x600/8e41f4/fff" alt="Card image cap">
          <div class="card-body">
            <h4 class="card-title">Card 7</h4>
            <p class="card-text">This is a longer card with supporting text below as a natural lead-in to additional
              content. This content is a little bit longer.</p>
            <p class="card-text"><small class="text-muted">Last updated 3 mins ago</small></p>
          </div>
        </div>
      </div>
    </div>
    <!--prev-->
    <a class="carousel-control-prev" href="#myCarousel" role="button" data-slide="prev">
      <span class="carousel-control-prev-icon" aria-hidden="true"></span>
      <span class="sr-only">Previous</span>
    </a>
    <!--next-->
    <a class="carousel-control-next" href="#myCarousel" role="button" data-slide="next">
      <span class="carousel-control-next-icon" aria-hidden="true"></span>
      <span class="sr-only">Next</span>
    </a>
  </div>
</div>

CSS

[data-slide] {
  background-color: rgba(51, 170, 51, 0.4);
}
@media (min-width: 768px) {
  /* show 3 items */
  .carousel-inner .active,
  .carousel-inner .active + .carousel-item,
  .carousel-inner .active + .carousel-item + .carousel-item {
    display: block;
  }

  .carousel-inner
    .carousel-item.active:not(.carousel-item-right):not(.carousel-item-left),
  .carousel-inner
    .carousel-item.active:not(.carousel-item-right):not(.carousel-item-left)
    + .carousel-item,
  .carousel-inner
    .carousel-item.active:not(.carousel-item-right):not(.carousel-item-left)
    + .carousel-item
    + .carousel-item {
    transition: none;
  }

  .carousel-inner .carousel-item-next,
  .carousel-inner .carousel-item-prev {
    position: relative;
    -webkit-transform: translate3d(0, 0, 0);
    transform: translate3d(0, 0, 0);
  }

  .carousel-inner
    .active.carousel-item
    + .carousel-item
    + .carousel-item
    + .carousel-item {
    position: absolute;
    top: 0;
    right: -33.3333%;
    z-index: -1;
    display: block;
    visibility: visible;
  }

  /* left or forward direction */
  .active.carousel-item-left + .carousel-item-next.carousel-item-left,
  .carousel-item-next.carousel-item-left + .carousel-item,
  .carousel-item-next.carousel-item-left + .carousel-item + .carousel-item,
  .carousel-item-next.carousel-item-left
    + .carousel-item
    + .carousel-item
    + .carousel-item {
    position: relative;
    -webkit-transform: translate3d(-100%, 0, 0);
    transform: translate3d(-100%, 0, 0);
    visibility: visible;
  }

  /* farthest right hidden item must be abso position for animations */
  .carousel-inner .carousel-item-prev.carousel-item-right {
    position: absolute;
    top: 0;
    left: 0;
    z-index: -1;
    display: block;
    visibility: visible;
  }

  /* right or prev direction */
  .active.carousel-item-right + .carousel-item-prev.carousel-item-right,
  .carousel-item-prev.carousel-item-right + .carousel-item,
  .carousel-item-prev.carousel-item-right + .carousel-item + .carousel-item,
  .carousel-item-prev.carousel-item-right
    + .carousel-item
    + .carousel-item
    + .carousel-item {
    position: relative;
    -webkit-transform: translate3d(100%, 0, 0);
    transform: translate3d(100%, 0, 0);
    visibility: visible;
    display: block;
    visibility: visible;
  }
}

JS

$(document).ready(function () {
  console.clear();
  $("#myCarousel").on("slide.bs.carousel", function (e) {
    var $e = $(e.relatedTarget);
    var idx = $e.index();
    var itemsPerSlide = 4;
    var totalItems = $(".carousel-item").length;
    if (idx >= totalItems - (itemsPerSlide - 1)) {
      var it = itemsPerSlide - (totalItems - idx);
      for (var i = 0; i < it; i++) {
        if (window.CP.shouldStopExecution(0)) break;
        // append slides to end
        if (e.direction == "left") {
          $(".carousel-item").eq(i).appendTo(".carousel-inner");
        } else {
          $(".carousel-item").eq(0).appendTo($(this).find(".carousel-inner"));
        }
      }
      window.CP.exitedLoop(0);
    }
  });
});

Live Preview

See the Pen Bootstrap 4 card slider by dimas lanjaka (@dimaslanjaka) on CodePen.