HTML5 Migration

Migrating from HTML4 to HTML5

This chapter explains how to migrate from a typical HTML4 page to a typical HTML5 page.

This chapter demonstrates how to convert an existing HTML4 page to an HTML5 page without destroying the original content and structure.

Note:You can use the same techniques to migrate from HTML4 and XHTML to HTML5.

Typical HTML4 Typical HTML5
<div id="header"> <header>
<div id="menu"> <nav>
<div id="content"> <section>
<div id="post"> <article>
<div id="footer"> <footer>

Typical HTML4 page

Example

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
"http://www.w3.org/TR/html4/loose.dtd">
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html;charset=utf-8">
<title>HTML4</title>
<style>
  body {font-family:Verdana,sans-serif;font-size:0.8em;}
  div#header,div#footer,div#content,div#post 
  {border:1px solid grey;margin:5px;margin-bottom:15px;padding:8px;background-color:white;}
  div#header,div#footer {color:white;background-color:#444;margin-bottom:5px;}
  div#content {background-color:#ddd;}
  div#menu ul {margin:0;padding:0;}
  div#menu ul li {display:inline; margin:5px;}
</style>
</head>
<body>
<div id="header">
  <h1>Monday Times</h1>
</div>
<div id="menu">
  <ul>
    <li>News</li>
    <li>Sports</li>
    <li>Weather</li>
  </ul>
</div>
<div id="content">
<h2>News Section</h2>
<div id="post">
  <h2>News Article</h2>
  <p>Ipsum lurum hurum turum ipsum lurum hurum turum ipsum lurum hurum turum ipsum 
  lurum hurum turum.</p>
  <p>Ipsum lurum hurum turum ipsum lurum hurum turum ipsum lurum hurum turum ipsum 
  lurum hurum turum.</p>
</div>
<div id="post">
  <h2>News Article</h2>
  <p>Ipsum lurum hurum turum ipsum lurum hurum turum ipsum lurum hurum turum ipsum 
  lurum hurum turum.</p>
  <p>Ipsum lurum hurum turum ipsum lurum hurum turum ipsum lurum hurum turum ipsum 
  lurum hurum turum.</p>
</div>
</div>
<div id="footer">
  <p>© 2014 Monday Times. All rights reserved.</p>
</div>
</body>
</html>

Try It Yourself

Change to HTML5 Doctype

Modify document type from HTML4 doctype:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
"http://www.w3.org/TR/html4/loose.dtd">

Change to HTML5 doctype:

<!DOCTYPE html>

Try It Yourself

Change to HTML5 encoding

Modify encoding information from HTML4:

<meta http-equiv="Content-Type" content="text/html;charset=utf-8">

Change to HTML5:

<meta charset="utf-8">

Try It Yourself

Add shiv

All modern browsers support HTML5 semantic elements.

In addition, you can "teach" old browsers how to handle "unknown elements".

Shiv added for Internet Explorer support:

<![if lt IE 9]>
  <script src="http://html5shiv.googlecode.com/svn/trunk/html5.js"></script>
<![endif]-->

Try It Yourself

Note:Read more about shiv in HTML5 browser support.

Add CSS for HTML5 semantic elements

Please see the existing CSS styles:

div#header, div#footer, div#content, div#post {
    border: 1px solid grey; margin: 5px; margin-bottom: 15px; padding: 8px; background-color: white;
}
div#header, div#footer {
    color:white;background-color:#444;margin-bottom:5px;
}
div#content {
    background-color:#ddd;
}
div#menu ul {
    margin:0;padding:0;
}
div#menu ul li {
    display:inline; margin:5px;
}
Duplicate with equal CSS styles for HTML5 semantic elements:
header,footer,section,article {
    border: 1px solid grey; margin: 5px; margin-bottom: 15px; padding: 8px; background-color: white;
}
header,footer {
    color:white;background-color:#444;margin-bottom:5px;
}
section {
    background-color:#ddd;
}
nav ul {
    margin:0;padding:0;
}
nav ul li {
    display:inline; margin:5px;
}

Try It Yourself

Change to HTML5 <header> and <footer>

Modify the <div> elements with id="header" and id="footer":

<div id="header">
  <h1>Monday Times</h1>
</div>
.
.
.
<div id="footer">
  <p>© 2016 CodeW3C.com. All rights reserved.</p>
</div>

Modify to HTML5 semantic elements <header> and <footer>:

<header>
  <h1>Monday Times</h1>
</header>
.
.
.
<footer>
  <p>© 2016 CodeW3C.com. All rights reserved.</p>
</footer>

Try It Yourself

Change to HTML5 <nav>

The <div> element with id="menu":

<div id="menu">
  <ul>
    <li>News</li>
    <li>Sports</a></li>
    <li>Weather</li>
  </ul>
</div>

Modify to HTML5 semantic element <nav>:

<nav>
  <ul>
    <li>News</li>
    <li>Sports</a></li>
    <li>Weather</li>
  </ul>
</nav>

Try It Yourself

Change to HTML5 <section>

The <div> element with id="content":

<div id="content">
.
.
.
</div>

Modify to HTML5 semantic elements <section>:

<section>
.
.
.
</section>

Try It Yourself

Change to HTML5 <article>

All <div> elements with class="post":

<div class="post">
  <h2>News Article</h2>
  <p>Ipsum lurum hurum turum ipsum lurum hurum turum ipsum lurum hurum turum ipsum 
  lurum hurum turum.</p>
</div>

Modify to HTML5 semantic elements <article>:

<article>
  <h2>News Article</h2>
  <p>Ipsum lurum hurum turum ipsum lurum hurum turum ipsum lurum hurum turum ipsum 
  lurum hurum turum.</p>
</article>

Try It Yourself

Remove these 'no longer needed' styles:

div#header, div#footer, div#content, div#post {
    border: 1px solid grey; margin: 5px; margin-bottom: 15px; padding: 8px; background-color: white;
}
div#header, div#footer {
    color:white;background-color:#444;margin-bottom:5px;
}
div#content {
    background-color:#ddd;
}
div#menu ul {
    margin:0;padding:0;
}
div#menu ul li {
    display:inline; margin:5px;
}

Try It Yourself

Typical HTML5 page

You can delete the <head> tag. They are no longer needed in HTML5:

Example

<!DOCTYPE html>
<html lang="en">
<title>HTML5</title>
<meta charset="utf-8">
<![if lt IE 9]>
<script src="http://html5shiv.googlecode.com/svn/trunk/html5.js">
</script>
<![endif]-->
<style>
body {
    font-family: Verdana, sans-serif; font-size: 0.8em;
}
header,footer,section,article {
    border:1px solid grey;
    margin:5px;margin-bottom:15px;padding:8px;
    background-color:white;
}
header,footer {
    color:white;background-color:#444;margin-bottom:5px;
}
section {
    background-color:#ddd;
}
nav ul {
    margin:0;padding:0;
}
nav ul li {
    display:inline; margin:5px;
}
</style>
<body>
<header>
  <h1>Monday Times</h1>
</header>
<nav>
  <ul>
    <li>News</li>
    <li>Sports</li>
    <li>Weather</li>
  </ul>
</nav>
<section>
<h2>News Section</h2>
<div id="post">
  <h2>News Article</h2>
  <p>Ipsum lurum hurum turum ipsum lurum hurum turum ipsum lurum hurum turum ipsum 
  lurum hurum turum.</p>
  <p>Ipsum lurum hurum turum ipsum lurum hurum turum ipsum lurum hurum turum ipsum 
  lurum hurum turum.</p>
  <p>Ipsum lurum hurum turum ipsum lurum hurum turum ipsum lurum hurum turum ipsum 
  lurum hurum turum.</p>
</div>
<div id="post">
<h2>News Article</h2>
  <p>Ipsum lurum hurum turum ipsum lurum hurum turum ipsum lurum hurum turum ipsum 
  lurum hurum turum.</p>
  <p>Ipsum lurum hurum turum ipsum lurum hurum turum ipsum lurum hurum turum ipsum 
  lurum hurum turum.</p>
  <p>Ipsum lurum hurum turum ipsum lurum hurum turum ipsum lurum hurum turum ipsum 
  lurum hurum turum.</p>
</div>
</section>
<footer>
  <p>© 2014 Monday Times. All rights reserved.</p>
</footer>
</body>
</html>

Try It Yourself

Differences between <article>, <section>, and <div>：

In the HTML5 standard, the differences between <article>, <section>, and <div> are minimal and confusing.

In the HTML5 standard, the <section> element is positioned as a block-level element for related elements.

The <article> element is defined as a complete, self-contained block for related elements.

The <div> element is defined as a block-level child element.

How can we understand this?

In the above examples, we used <section> as a container for related <articles>.

However, we can also use <article> as a container for articles.

Here are some different examples：

The <article> within <article>：
<article>
<h2>Famous Cities</h2>
<article>
<h2>London</h2>
<p>London is the capital city of England. It is the most populous city in the United Kingdom,</p>
with a metropolitan area of over 13 million inhabitants.</p>
</article>
<article>
<h2>Paris</h2>
<p>Paris is the capital and most populous city of France.</p>
</article>
<article>
<h2>Tokyo</h2>
<p>Tokyo is the capital of Japan, the center of the Greater Tokyo Area,</p>
and the most populous metropolitan area in the world.</p>
</article>
</article>

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<article> Within <div>：</article>
<article>
<h2>Famous Cities</h2>
<div class="city">
<h2>London</h2>
<p>London is the capital city of England. It is the most populous city in the United Kingdom,</p>
with a metropolitan area of over 13 million inhabitants.</p>
</div>
<div class="city">
<h2>Paris</h2>
<p>Paris is the capital and most populous city of France.</p>
</div>
<div class="city">
<h2>Tokyo</h2>
<p>Tokyo is the capital of Japan, the center of the Greater Tokyo Area,</p>
and the most populous metropolitan area in the world.</p>
</div>
</article>

Try It Yourself

<article> Within <section> Within <div>：</article>
<article>
<section>
<h2>Famous Cities</h2>
<div class="city">
<h2>London</h2>
<p>London is the capital city of England. It is the most populous city in the United Kingdom,</p>
with a metropolitan area of over 13 million inhabitants.</p>
</div>
<div class="city">
<h2>Paris</h2>
<p>Paris is the capital and most populous city of France.</p>
</div>
<div class="city">
<h2>Tokyo</h2>
<p>Tokyo is the capital of Japan, the center of the Greater Tokyo Area,</p>
and the most populous metropolitan area in the world.</p>
</div>
</section>
<section>
<h2>Famous Countries</h2>
<div class="country">
<h2>England</h2>
<p>London is the capital city of England. It is the most populous city in the United Kingdom,</p>
with a metropolitan area of over 13 million inhabitants.</p>
</div>
<div class="country">
<h2>France</h2>
<p>Paris is the capital and most populous city of France.</p>
</div>
<div class="country">
<h2>Japan</h2>
<p>Tokyo is the capital of Japan, the center of the Greater Tokyo Area,</p>
and the most populous metropolitan area in the world.</p>
</div>
</section>
</article>

Try It Yourself