Responsive images

Images in Bootstrap are made responsive with .img-fluid. This applies max-width: 100%; and height: auto; to the image so that it scales with the parent element.

Images - 图1

  1. <img src="..." class="img-fluid" alt="...">

Image thumbnails

In addition to our border-radius utilities, you can use .img-thumbnail to give an image a rounded 1px border appearance.

Images - 图2

  1. <img src="..." class="img-thumbnail" alt="...">

Aligning images

Align images with the helper float classes or text alignment classes. block-level images can be centered using the .mx-auto margin utility class.

Images - 图3

  1. <img src="..." class="rounded float-start" alt="...">
  2. <img src="..." class="rounded float-end" alt="...">

Images - 图4

  1. <img src="..." class="rounded mx-auto d-block" alt="...">

Images - 图5

  1. <div class="text-center">
  2. <img src="..." class="rounded" alt="...">
  3. </div>

Picture

If you are using the <picture> element to specify multiple <source> elements for a specific <img>, make sure to add the .img-* classes to the <img> and not to the <picture> tag.

  1. ​<picture>
  2. <source srcset="..." type="image/svg+xml">
  3. <img src="..." class="img-fluid img-thumbnail" alt="...">
  4. </picture>