Stretch and fill image in Bootstrap carousel

Question

I am using bootstrap carousal and having some problem with image height and width. Even though I define it in the img attribute it still displays as original resolution. Following is the code I am using:

<div class="col-md-6 col-sm-6">
    <div id="myCarousel" class="carousel slide">
        <div class="carousel-inner">
            <div class="item active">
                <img src="http://placehold.it/650x450/aaa&text=Item 3" height="300" width="300" />
            </div>
            <div class="item">
                <img src="http://placehold.it/350x350/aaa&text=Item 3" height="300" width="300" />
            </div>
            <div class="item">
                <img src="http://placehold.it/350x350/aaa&text=Item 3" height="300" width="300" />
            </div>
        </div>
        <!-- Controls -->
        <a class="left carousel-control" href="#myCarousel" data-slide="prev">
            <span class="icon-prev"></span>
        </a>
        <a class="right carousel-control" href="#myCarousel" data-slide="next">
            <span class="icon-next"></span>
        </a>
    </div>
</div>

Here is demo of that.

What should I do to fill the image in a certain height and width regardless of its original resolution?

Answer 1

You can place height in css and add !important because bootstrap is overriding your height with auto , and object-fit:cover; will work like background size cover a fiddle

.carousel{
  width:300px;
}
.item img{
  object-fit:cover;
  height:300px !important;
  width:350px;
}

Answer 2

That you have width in placeholder should not matter, put this in your css and it should work, If it works you can try remove !important.

 .carousel img {
        width:100% !important;
        min-width:100 !important;
        height: auto;
    }

.img-responsive in bootstrap will just set the width to 100%, So in the case that the image original proportions are less than carousel width it will not fill it out.

Answer 3

You can use background-size: cover, while still having hidden <img> element for SEO and semantic purposes. Single img url is used both times, so there's no additional loading, and background-size is well supported (unlike object-fit which lacks support in IE, Edge and Android < 4.4.4).

Fiddle Demo

HTML change:

<div class="item" style="background-image: url(http://placehold.it/400x400);">
  <img src="http://placehold.it/400x400"/>
</div>

CSS change:

.carousel {
  /* any dimensions are fine, it can be responsive with max-width */
  width: 300px;
  height: 350px;
}

.carousel-inner {
  /* make sure your .items will get correct height */
  height: 100%;
}

.item {
  background-size: cover;
  background-position: 50% 50%;
  width: 100%;
  height: 100%;
}

.item img {
  visibility: hidden;
}