W3Schools
home HOME Tutorials | References | Examples | Forum | About
Search W3Schools :

XHTML Tutorial
XHTML HOME
XHTML Introduction
XHTML Why
XHTML vs HTML
XHTML Syntax
XHTML DTD
XHTML HowTo
XHTML Validation
XHTML Modules
XHTML Summary

Quiz/Exam
XHTML Quiz
XHTML Exam

References
XHTML Tag List
XHTML Attributes
XHTML Events
XHTML Colornames
XHTML Character Sets
XHTML ASCII
XHTML ISO-8859-1
XHTML Symbols
XHTML URL Encode
XHTML Lang Codes
HTTP Messages

Selected Reading
Web Statistics
Web Glossary
Web Hosting
Web Quality

W3Schools Tutorials
W3Schools Forum

Helping W3Schools

Differences Between XHTML And HTML

Previous Next

You can prepare yourself for XHTML by starting to write strict HTML.


How To Get Ready For XHTML

XHTML is not very different from the HTML 4.01 standard.

So, bringing your code up to the 4.01 standard is a good start. Our complete HTML 4.01 reference can help you with that.

In addition, you should start NOW to write your HTML code in lowercase letters, and NEVER skip ending tags (like </p>).

Happy coding!


The Most Important Differences:

  • XHTML elements must be properly nested
  • XHTML elements must always be closed
  • XHTML elements must be in lowercase
  • XHTML documents must have one root element

XHTML Elements Must Be Properly Nested

In HTML, some elements can be improperly nested within each other, like this:

<b><i>This text is bold and italic</b></i>

In XHTML, all elements must be properly nested within each other, like this:

<b><i>This text is bold and italic</i></b>

Note: A common mistake with nested lists, is to forget that the inside list must be within <li> and </li> tags.

This is wrong:

<ul>
  <li>Coffee</li>
  <li>Tea
    <ul>
      <li>Black tea</li>
      <li>Green tea</li>
    </ul>
  <li>Milk</li>
</ul>

This is correct:

<ul>
  <li>Coffee</li>
  <li>Tea
    <ul>
      <li>Black tea</li>
      <li>Green tea</li>
    </ul>
  </li>
  <li>Milk</li>
</ul>

Notice that we have inserted a </li> tag after the </ul> tag in the "correct" code example.


XHTML Elements Must Always Be Closed

Non-empty elements must have an end tag.

This is wrong:

<p>This is a paragraph
<p>This is another paragraph

This is correct:

<p>This is a paragraph</p>
<p>This is another paragraph</p>


Empty Elements Must Also Be Closed

Empty elements must either have an end tag or the start tag must end with />.

This is wrong:

A break: <br>
A horizontal rule: <hr>
An image: <img src="happy.gif" alt="Happy face">

This is correct:

A break: <br />
A horizontal rule: <hr />
An image: <img src="happy.gif" alt="Happy face" />


XHTML Elements Must Be In Lower Case

The XHTML specification defines that the tag names and attributes need to be lower case.

This is wrong:

<BODY>
<P>This is a paragraph</P>
</BODY>

This is correct:

<body>
<p>This is a paragraph</p>
</body>


XHTML Documents Must Have One Root Element

All XHTML elements must be nested within the <html> root element. All other elements can have sub (children) elements. Sub elements must be in pairs and correctly nested within their parent element. The basic document structure is:

<html>
<head> ... </head>
<body> ... </body>
</html>


Previous Next


The tools you need to build your web project!

Instant Demo

Ektron CMS400.NET Version 7.6 delivers all of the flexibility and features you need to deploy the Web site you want, quickly and efficiently.

learn more...

 

 

 

6 ways to take your site to the next level with Ektron:

Social Networking Create site stickiness through social networking. Keep it personal, relevant and interactive and they'll come back for more.
Open API Keep it open. Your site needs to be ready and able to connect to outside services. Ektron's open API gives you maximum flexibility.
Document Management Streamline content and document management. Users need to quickly and intuitively find and add information.
Content Authors Empower your content authors. Reduce IT bottlenecks by allowing business users to create and edit Web content and forms.
Taxonomy Climb to the top of search rankings. SEO tools, URL aliasing and eCommerce for your digital marketing strategy
Web 2.0 Tools Add powerful Web 2.0 tools like blogs, wikis, forums, geo-mapping, rating systems and RSS feeds easily.
See why there are 20,000+ Ektron integrations worldwide.
Request an INSTANT DEMO or download a FREE TRIAL today.


Jump to: Top of Page or HOME or Printer Friendly Printer friendly page

W3Schools provides material for training only. We do not warrant the correctness of its contents. The risk from using it lies entirely with the user. While using this site, you agree to have read and accepted our terms of use and privacy policy.

Copyright 1999-2008 by Refsnes Data. All Rights Reserved.

Validate Validate W3C-WAI level A conformance icon W3Schools was converted to XHTML in December 1999
IISProtect
Password Protect
Your Web Pages
WEB HOSTING
$15 Domain Name
Registration
Save $20 / year!
Buy UK Domain Names
Register Domain Names
Cheap Domain Names
Cheap Web Hosting
Best Web Hosting
PHP MySQL Hosting
Top 10 Web Hosting
UK Reseller Hosting
Web Hosting
WEB BUILDING
Website Templates
Flash Templates
Website Builder
Internet Business Opportunity
Custom Programming
FREE Trial or Demo
Web Content Manager
Forms,Web Alerts,RSS
Download XML editor
Free Flash Website
EDUCATION
US Web Design Schools
HTML Exam