AMP
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amp-img

Introduction

AMP HTML files don't support the normal HTML img tag. With amp-img AMP provides a powerful replacement.

Setup

amp-img is a built-in element and is automatically imported via the AMP runtime.

<script async src="https://cdn.ampproject.org/v0.js"></script>

You can use the amp-bind extension for dynamically changing an image.

<script async custom-element="amp-bind" src="https://cdn.ampproject.org/v0/amp-bind-0.1.js"></script>

Basic usage

A simple responsive image - width and height are used to determine the aspect ratio. Use alt to specify text that can act as an alternative for the image.

<amp-img src="/static/samples/img/amp.jpg" width="1080" height="610" layout="responsive" alt="AMP"></amp-img>

srcset

Use srcset to specify different images for varying viewport widths and pixel densities (change the width of your browser windows to test it).

<amp-img src="/static/samples/img/amp.jpg" srcset="/static/samples/img/amp.jpg 1080w, /static/samples/img/amp-900.jpg 900w, /static/samples/img/amp-800.jpg 800w,
/static/samples/img/amp-700.jpg 700w, /static/samples/img/amp-600.jpg 600w, /static/samples/img/amp-500.jpg 500w, /static/samples/img/amp-400.jpg 400w,
/static/samples/img/amp-300.jpg 300w, /static/samples/img/amp-200.jpg 200w, /static/samples/img/amp-100.jpg 100w" width="1080" height="610" layout="responsive" alt="AMP"></amp-img>

Offline fallback

amp-img supports AMP's common attributes, which means you can show a fallback in case the image couldn't be loaded. This is great for adding offline support to your AMPs.

offline
<amp-img src="/static/samples/img/does-not-exist.jpg" width="300" height="100" layout="responsive" alt="a non-existent image">
  <div fallback>offline</div>
</amp-img>

No script

If you want to ensure that users with JavaScript disabled can see your images, you can add an additional img element inside a noscript tag. This also makes it possible for webcrawlers without JavaScript runtime to discover your images.

<amp-img src="/static/samples/img/amp.jpg" width="475" height="268" layout="responsive" alt="AMP">
  <noscript>
    <img src="/static/samples/img/amp.jpg" width="475" height="268" alt="AMP">
  </noscript>
</amp-img>

Hiding the loading indicator

Use the noloading attribute to hide the loading indicators on page load. This is recommended for logos and small images/icons.

<amp-img src="/static/samples/img/amp_by_example_logo.svg" width="208" height="40" alt="AMP by Example" noloading></amp-img>

Dynamically changing the src

You can use amp-bind to dynamically change the src URL of an amp-img. Remember to also change the alt if the content/meaning of the image changes.

<amp-img src="https://unsplash.it/300/200/?image=100" width="300" height="200" alt="Example image" [src]="myImageUrl" [alt]="myImageAlt">
</amp-img>
<button on="tap:AMP.setState({ myImageUrl: 'https://unsplash.it/300/200/?image=200', myImageAlt: 'Another example image' })">Change image</button>

Vertically centering an amp-img

Here is a simple approach to vertically center an amp-img using the flex layout (src):

<div class="outer">
   <amp-img class="inner" layout="responsive" src="https://unsplash.it/300/200" width="3" height="2" alt="a vertically centered amp-img">
   </amp-img>
 </div>

...and here is the CSS:

.inner{
  flex-basis: 0;
  -ms-flex-preferred-size: 0;
  -webkit-box-flex: 1;
  -ms-flex-positive: 1;
  flex-grow: 1;
}
.outer {
  height: 320px; /* adjust to your needs */
  display: flex;
  flex-wrap: wrap;
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center;
}
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