Difference Between HTML and XHTML – Basic and Important Comparisons
The main difference between HTML (HyperText Markup Language) and XHTML (Extensible HyperText Markup Language) lies in their syntax and rules for structuring web content.
If you are learning web development and are tasked to create well-structured pages, knowing the difference between HTML and XHTML should help.
Both are markup languages inserted in text documents to control the structure based on certain rules and semantics. The key differences between HTML and XHTML lie in their syntax, structure, and standards compliance. All these factors impact how web pages are coded and rendered in browsers.
Key Comparisons: HTML vs. XHTML
| Aspect | HTML | XHTML |
|---|---|---|
| Syntax Rules | You can get away with mistakes or omissions | Code must be structured and follow XML rules |
| Case Sensitivity | Not sensitive to capitalization in tags/attributes | Capitalization in tags/attributes must be consistent |
| Self-Closing Tags | Some tags don’t need explicit closure | Every self-closing tag must be closed with a slash |
| Attribute Quoting | Attribute values can sometimes be unquoted | Quotes must always be used around attribute values |
| DOCTYPE Declaration | Often optional, not always needed | Crucial for indicating version and standards |
| Error Handling | Browsers are forgiving with mistakes | Mistakes can lead to unexpected display issues |
| Whitespace Handling | Extra spaces/line breaks may not matter | Spaces/breaks can impact appearance and layout |
| Rendering Mode | Browsers can interpret things differently | There’s a standard way to render for consistency |
| Script & Style Tags | Can be used as you want | Need to be enclosed differently for proper parsing |
| Required Elements | Not everything needs perfect structuring | Every element should be properly nested/closed |
| Media & MIME Types | Limited flexibility in specifying media | More options available for specifying media |
| Browser Compatibility | Older code might work in newer browsers | More careful adherence to rules may be needed |
| Deprecated Elements | Some old elements are still functional | Older elements might not function as expected |
Best-suited HTML & CSS courses for you
Learn HTML & CSS with these high-rated online courses
Defining HTML
The full form of HTML is HyperText Markup Language. It is used for describing how the content on a webpage would appear.
Learn what HTML is in detail.
In the early 1990s, HTML was created by Tim Berners-Lee as a simple markup language. The goal was to share scientific documents over the Internet. HTML helped present structured information to users uniformly and readably regardless of the device.
So, what is the role of HTML in web pages you view?
The article’s title, headings, paragraphs, images, and links are HTML tags. This careful structuring enhances readability and ensures that search engines can understand and interpret the content accurately.
Do read about the Difference between HTML and CSS
HTML Code Example
Here is a basic example of an HTML code.
<!DOCTYPE html><html lang="en"><head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Sample Article</title></head><body> <h1>Welcome to the World of HTML</h1>
<h2>Introduction</h2> <p>In this article, we will explore the basics of HTML and create a simple web page.</p>
<h2>HTML Structure</h2> <p>HTML stands for Hypertext Markup Language. It's used to structure content on the web.</p>
<h2>Creating Paragraphs</h2> <p>Paragraphs are created using the <p> tag. They provide structure to your content.</p> <h2>Headers and Subheaders</h2> <h3>H3 Subheader Example</h3> <p>Headers and subheaders give hierarchy to your content, making it more readable.</p>
<h2>Tables</h2> <table border="1"> <tr> <th>Name</th> <th>Age</th> </tr> <tr> <td>John</td> <td>25</td> </tr> <tr> <td>Mary</td> <td>30</td> </tr> </table>
<h2>Conclusion</h2> <p>HTML is the foundation of the web. With its simple tags, you can create diverse content.</p></body></html>
The Output
More to Read
Defining XHTML
The full form of XHTML is Extensible HyperText Markup Language, which means HTML has to be written as XML. XHTML is a separate language with its own document-type definitions, and it extends the HTML 4.0 capability. Every tag must be properly closed, every element nested correctly, and every attribute quoted.
This makes XHTML more modular and stricter in following XML syntax rules around elements, attributes, and document structure.
It came around 1998, as an attempt to reformulate HTML into a valid XML format. This made XHTML more extensible and brought stricter syntax rules than the more lenient HTML.
Also, explore the Difference between XML and HTML.
XHTML Code Example
<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Sample Article in XHTML</title></head><body> <h1>Welcome to the World of XHTML</h1>
<h2>Introduction</h2> <p>In this article, we'll explore the basics of XHTML and create a simple web page.</p>
<h2>XHTML Structure</h2> <p>XHTML, or Extensible Hypertext Markup Language, provides stricter rules for structuring web content.</p>
<h2>Creating Paragraphs</h2> <p>Paragraphs are created using the <p> tag. They maintain consistent structure in XHTML documents.</p> <h2>Headers and Subheaders</h2> <h3>H3 Subheader Example</h3> <p>Headers and subheaders help organize content hierarchically, improving readability.</p>
<h2>Tables</h2> <table border="1"> <tr> <th>Name</th> <th>Age</th> </tr> <tr> <td>John</td> <td>25</td> </tr> <tr> <td>Mary</td> <td>30</td> </tr> </table>
<h2>Conclusion</h2> <p>XHTML enforces structure and adherence to standards, contributing to a well-organized web.</p></body></html>
The Output
Rules in HTML versus XHTML
| Rule | HTML | XHTML |
| Tag Closures | Some tags can be left unclosed. | All tags must be properly closed. |
| Case Sensitivity | Tags and attributes are case-insensitive. | Tags and attributes are case-sensitive. |
| Quotation Marks | Attribute values can use single or double quotes, or no quotes. | Attribute values must be enclosed in double quotes. |
| Self-Closing Tags | Void elements can be self-closed without a trailing slash. | Void elements must be self-closed with a trailing slash. |
| Benefit | Offers more leniency for quick development. | Ensures well-formed, standardized documents. |
Tag Closures Example
HTML (Unclosed Tags)
<p>This is an unclosed paragraph.<img src="image.jpg"><br>
XHTML (Properly Closed Tags)
<p>This is a closed paragraph.</p><img src="image.jpg" /><br />
Case Sensitivity Example
HTML (Case-Insensitive Tags)
<P>This is a Paragraph.</P><ImG src="image.jpg">
XHTML (Case-Sensitive Tags)
<p>This is a paragraph.</p><img src="image.jpg" />
Self-Closing Tags Example
HTML (Self-Closed Tags)
<img src="image.jpg"><br><input type="text" name="username">
XHTML (Self-Closed Tags with Slash)
<img src="image.jpg" /><br /><input type="text" name="username" />
Compatibility with Different Browsers: HTML vs. XHTML
HTML is backwards compatible. But older HTML code may cause problems in rendering in newer browsers. In such cases, developers make adjustments to their code to ensure they are compatible enough.
On the other hand, XHTML works seamlessly with newer browsers. Because it has stricter rules, developers are able to maintain and debug it.
Uses of HTML vs. XHTML
So here are places where HTML is present.
- The structure of web pages is basically HTML. It defines headings, paragraphs, lists, images, links, and more.
- HTML makes text bold, italic, underlined, and to control its size and color.
- The clickable links that take you to other pages or websites when you click on them are HTML too.
- Even used to insert and display images on web pages.
- Creating both ordered (numbered) and unordered (bulleted) lists with HTML.
- Forms that you fill out on websites, like login forms, search boxes, and feedback forms are of HTML.
Places you will find XHTML.
- Back in the day, some websites were built using XHTML to make sure they worked well with different devices and browsers.
- XHTML was used to create pages that could be easily viewed on different devices, like computers and phones.
- Since XHTML follows stricter rules, it was used for creating documents where maintaining a consistent structure was crucial.
Today, HTML5 has become the standard for web development. It’s a more flexible and forgiving version of HTML. XHTML’s strict rules sometimes made it harder to work with, and the web development community has largely transitioned to using HTML5 for its benefits.
Aquib is a seasoned wordsmith, having penned countless blogs for Indian and international brands. These days, he's all about digital marketing and core management subjects - not to mention his unwavering commitment ... Read Full Bio
Top Picks & New Arrivals
