Today, the use of mobile phones are growing drastically. Mobile devices have reformed our way of accessing information. Nowadays we consume a vast amount of data through our mobile phones. So mobile web becomes an indivisible part of our daily life. Publishers utilized these mobile web to reach the targeted mobile users. But the experience of mobile browsing is often not appeasing and need to wait a long time for the pages to be loaded. So the  requirement of better AMP optimization techniques is highly recommended.

Due to the bad website experience, publishers lost their customers and business to a great extend. In order to avoid this situation, Google introduced a new open source initiative called Accelerated Mobile Pages(AMP), which aims to improve the performance of mobile web. We can perform AMP optimization techniques to improve the performance of websites on mobile.

How to make fast web pages?

• Simplify web pages by using less Javascript files.
• Optimize bandwidth
  ○ Use best content for device (image resolution etc.)
  ○ Parallelize the loading (asynchronous load)
• Store local copies of web pages on Content Delivery Servers.

Content Delivery Networks (CDN)

Content delivery networks is a collection of web servers that are distributed geographically across the earth. It’s goal is to serve the content to end-users with high availability and performance. CDNs virtually reduce the physical distance between the source server and end-user. When we distribute our content through CDNs,  it routes the user requests to the closest CDN server according to the position of the end-user on internet. Usually, each CDNs will stores a cached version of its content in multiple geographical locations.

Commonly CDNs are used to host static contents like images, videos, CSS, JavaScript etc. But the use of single domain will cause limitation for simultaneous connections to the server. For CDN files, they are hosted on different servers. So, there is no limit for connections to a CND server. Through CDNs, we can  achieve better mobile performance optimization such as smaller bandwidth, load distribution and shorter load time.

Accelerated Mobile Pages(AMP)

AMP Project is an initiative from Google to provide a solution for faster mobile websites. It is an open source coding standard for publishers. The main goal of the technology is to help the publishers to create mobile-friendly content and load it faster as possible. AMP optimization of web pages will provides content to the user much faster and brings better user experience. It does not tries to unify the appearance of web pages on mobile. But helps to create a common core and structure to speed up load times.

AMP pages are none other than HTML pages with a limited set of HTML tags. The use of limited HTML tags will reduce the load time of web pages. AMP HTML can be rendered on any modern browser. To optimize delivery times for pages, Google maintains a Google AMP Cache. AMP can improves server performance too. It can be an SEO activity focusing mobile users.

Google AMP Cache

AMP cache will  cache all AMP optimized pages and it serves to everyone at no cost. It means that the content provider does not have any additional work for caching AMP pages. The combination of caching distribution system and limited HTML structure will increase the speed of delivering content to the user.

AMP framework Components

This framework consists of three components:

• AMP HTML :

It is a standard HTML markup with web components.

• AMP JavaScript :

It will manage the resource loading.

• AMP Caches :

It helps to serve and validate AMP pages.

AMP Optimization of Web pages

This optimization technique makes the AMP pages really fast. The main idea is to restrict everything on the page, what could be extremely slow and provide another solution for the particular issue. It includes:

• Allows asynchronous scripts only
• Static sizes of all resources
• Don’t let extension mechanisms block rendering
• CSS style sheet limitation

1. Allows asynchronous scripts only

AMP Pages does not allow  any JavaScript that is synchronous. JavaScript files are usually synchronous. So it can modify basically all aspects of the page and cause delays during the page rendering. In AMP, JavaScript must be declared as async. It informs the browser that, the execution of JavaScript is not crucial to build the web page.

Example : <script src=”https://example.com/javascript.js” async></script>

2. Static sizes of all resources

The size of all external resources on the page like videos, images, advertisements, etc must be known in advance before downloading them. So that AMP can pre-determine each element’s size and position before the resources are downloaded. Hence AMP loads the layout of the page without waiting for any resources to download.

3. Don’t let extension mechanisms block rendering

Usually AMP doesn’t let extension mechanisms to block page rendering. If we want to use some social media embeds like tweets, instagram etc in our page. All these embeds always requires some additional HTTP requests to load. So we need to inform the AMP system that we will use some custom script which requires a custom tag. During this situation custom tag is mentioned in head of the page.  AMP will create a box for our custom tag before it knows what will be its content.

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

4. CSS style sheet limitation

Cascade style sheet(CSS) files are usually large and contains styles for the whole site. It can also delays the loading time of a web page to an extend. The size limit for custom AMP CSS is 50 kilobytes. So we must reduce the size of our external CSS to 50 KB. In order to avoid other http requests during page rendering, all the CSS must be written as inline.

AMP Optimization Steps :

• Include AMP symbol within the HTML tag.
• Add canonical tag.
• Include AMP library file.
• Specify a viewport.
• AMP CSS validation.
• AMP boiler plate.
• Replace <img> with <amp-img>
• Link AMP content
• AMP page validation

HTML page before AMP optimization

article.html file :

<!doctype html>
<html lang="en">
  <head>
    <title>News Article</title>
    <link href="base.css" rel="stylesheet" />
    <script type="text/javascript" src="base.js"></script>
  </head>
  <body>
    <header>
      News Site
    </header>
    <article>
      <h1>Article Name</h1>
      <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam egestas tortor sapien, non tristique ligula accumsan eu.</p>
    </article>
    <img src="mountains.jpg">
  </body>
</html>

1. Include AMP symbol  ⚡ within the HTML tag

• Copy  entire code from the HTML file( eg:  article.html ) and paste it into a new file.
• Save the new file as  article.amp.html.
• Add the attribute ⚡ to the <html> tag in the head section.

           Example: <html ⚡ lang="en">

2. Add canonical tag

• Every AMP document must posses a link referencing to its ‘canonical version’ of that document.
• We must provide the absolute URL of original HTML page.
• Then the tag must be included in head section.

   Example: <link rel="canonical" href="/article.html">

3. Include AMP library file

• To begin AMP optimization we should add AMP library file.
• It can help us to figure out,what all we need to fix.
• Tag must be included in the head section.

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

4. Specify a viewport

• AMP requires  definitons for width and minimum-scale for the viewport.
• Its values must be device-width and 1, respectively.
• Viewport is a common tag used in head section.

   Example: <meta name="viewport" content="width=device-width,minimum-scale=1,initial-scale=1">

5. AMP CSS validation

• In AMP page we cannot include external stylesheet.
• Reduce the size of  base.css file to 50 KB.
• Embed the style sheet within  <style amp-custom></style> tag as inline styles.

   Example: <style amp-custom>

                 /* The content from base.css */

            </style>

6. AMP boiler plate

• Add the AMP boilerplate code to the bottom of the <head> tag.
• Boilerplate helps to hide the content of body section until the AMP JavaScript library is loaded.
• It will helps to prevent unstyled content from rendering, also known as Flash Of Unstyled Content (FOUC).
• FOUC : It means a situation where a web page appears briefly with the browsers default styles prior to loading an external CSS.

AMP boiler plate code

7. Replace <img> with <amp-img>

• AMP designed special web component to replace the <img> tag with <amp-img> tag.
• In AMP, we need to define the width, height and layout for amp-img elements.
• So AMP can per-determine the aspect ratio of the element.
• layout attribute is used to specify, how we want the element to be positioned and scaled.
• Attribute layout =”responsive” is provided to inform that our image can be scaled and resize.
• But amp-img tag is added to the body section of the HTML page.

   Example:<amp-img src="mountains.jpg" layout="responsive" width="266" height="150"></amp-img>

8. Link AMP content

• The next step is to link the canonical version to the AMP page.
• This is achieved by including a <link rel="amphtml"> tag to the <head> section of the original non-AMP HTML page.
• While generating AMP versions of traditional non-AMP HTML pages.
• Both versions have generally the same content, but have different presentations.
• So we should treat the traditional HTML pages as the “canonical” pages.
• Pair the AMP pages with canonical pages.

   Example: <link rel="amphtml" href="/article.amp.html">

8. AMP Page Validation

• This is the last step in AMP optimization.
• Here we validate our AMP page created in AMP validator to check whether it is optimized or not.

AMP Page After Optimization

article.amp.html :

<!doctype html>
<html ⚡ lang="en">
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width,minimum-scale=1,initial-scale=1">
    <link rel="canonical" href="/article.html">
    <link rel="shortcut icon" href="amp_favicon.png">
    <title>News Article</title>
    <style amp-boilerplate>body{-webkit-animation:-amp-start 8s steps(1,end) 0s 1 normal both;-moz-animation:-amp-start 8s steps(1,end) 0s 1 normal both;-ms-animation:-amp-start 8s steps(1,end) 0s 1 normal both;animation:-amp-start 8s steps(1,end) 0s 1 normal both}@-webkit-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@-moz-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@-ms-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@-o-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}</style><noscript><style amp-boilerplate>body{-webkit-animation:none;-moz-animation:none;-ms-animation:none;animation:none}</style></noscript>
    <style amp-custom>
      body {
        width: auto;
        margin: 0;
        padding: 0;
      }
      header {
        background: Tomato;
        color: white;
        font-size: 2em;
        text-align: center;
      }
      h1 {
        margin: 0;
        padding: 0.5em;
        background: white;
        box-shadow: 0px 3px 5px grey;
      }
      p {
        padding: 0.5em;
        margin: 0.5em;
      }
    </style>
    <script async src="https://cdn.ampproject.org/v0.js"></script>
  </head>
  <body>
    <header>
      News Site
    </header>
    <article>
      <h1>Article Name</h1>
      <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam egestas tortor sapien, non tristique ligula accumsan eu.</p>
      <amp-img src="mountains.jpg" layout="responsive" width="266" height="150"></amp-img>
    </article>
  </body>
</html>