Bootstrap Images

Rounded Corners

The .img-rounded class adds rounded corners to an image (IE8 does not support rounded corners):

<img src="cinqueterre.jpg" class="img-rounded" alt="Cinque Terre">

Circle

The .img-circle class shapes the image to a circle (IE8 does not support rounded corners):

<img src="cinqueterre.jpg" class="img-circle" alt="Cinque Terre">

Thumbnail

The .img-thumbnail class shapes the image to a thumbnail:

<img src="cinqueterre.jpg" class="img-thumbnail" alt="Cinque Terre">

Responsive Images

Images come in all sizes. So do screens. Responsive images automatically adjust to fit the size of the screen.

Create responsive images by adding an .img-responsive class to the <img> tag. The image will then scale nicely to the parent element.

The .img-responsive class applies display: block; and max-width: 100%; and height: auto; to the image:

<img class="img-responsive" src="img_chania.jpg" alt="Chania">

Image Gallery

You can also use Bootstrap's grid system in conjunction with the .thumbnail class to create an image gallery.

 <div class="row">
  <div class="col-md-4">
    <div class="thumbnail">
      <a href="/w3images/lights.jpg">
        <img src="/w3images/lights.jpg" alt="Lights" style="width:100%">
        <div class="caption">
          <p>Lorem ipsum...</p>
        </div>
      </a>
    </div>
  </div>
  <div class="col-md-4">
    <div class="thumbnail">
      <a href="/w3images/nature.jpg">
        <img src="/w3images/nature.jpg" alt="Nature" style="width:100%">
        <div class="caption">
          <p>Lorem ipsum...</p>
        </div>
      </a>
    </div>
  </div>
  <div class="col-md-4">
    <div class="thumbnail">
      <a href="/w3images/fjords.jpg">
        <img src="/w3images/fjords.jpg" alt="Fjords" style="width:100%">
        <div class="caption">
          <p>Lorem ipsum...</p>
        </div>
      </a>
    </div>
  </div>
</div>

Responsive Embeds

Also let videos or slideshows scale properly on any device.

Classes can be applied directly to <iframe>, <embed>, <video>, and <object> elements.

The following example creates a responsive video by adding an .embed-responsive-item class to an <iframe> tag (the video will then scale nicely to the parent element). The containing <div> defines the aspect ratio of the video:

<div class="embed-responsive embed-responsive-16by9">
  <iframe class="embed-responsive-item" src="..."></iframe>
</div>

What is aspect ratio? 

The aspect ratio of an image describes the proportional relationship between its width and its height. Two common video aspect ratios are 4:3 (the universal video format of the 20th century), and 16:9 (universal for HD television and European digital television).

<!-- 16:9 aspect ratio -->
<div class="embed-responsive embed-responsive-16by9">
  <iframe class="embed-responsive-item" src="..."></iframe>
</div>

<!-- 4:3 aspect ratio -->
<div class="embed-responsive embed-responsive-4by3">
  <iframe class="embed-responsive-item" src="..."></iframe>
</div>