HTML vs. XHTML

30 March 2025 | Category: HTML

HTML and XHTML are both markup languages used to create web pages, but they have key differences in syntax, structure, and how browsers interpret them. This guide will explain the differences, advantages, and when to use each.

1. What is HTML?

HyperText Markup Language (HTML) is the standard language used to create web pages. It is flexible and does not strictly enforce syntax rules.

Example of an HTML Document:

<!DOCTYPE html>
<html>
<head>
    <title>HTML Example</title>
</head>
<body>
    <h1>Welcome to HTML</h1>
    <p>This is a basic HTML page.</p>
</body>
</html>

Key Features of HTML:

✅ Simple and easy to learn.
✅ Not case-sensitive (you can use <TITLE> or <title>).
✅ Allows some errors in syntax (browsers can correct mistakes).
✅ Uses a loose document structure.

2. What is XHTML?

Extensible HyperText Markup Language (XHTML) is a stricter and more structured version of HTML based on XML. It follows strict syntax rules and ensures web pages are well-formed.

Example of an XHTML Document:

<!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">
<head>
    <title>XHTML Example</title>
</head>
<body>
    <h1>Welcome to XHTML</h1>
    <p>This is a basic XHTML page.</p>
</body>
</html>

Key Features of XHTML:

✅ Stricter Syntax (must follow XML rules).
✅ Well-formed Code (all tags must be closed properly).
✅ Lowercase Tags (e.g., <title> instead of <TITLE>).
✅ Quotes Required for attribute values (<img src="image.jpg" />).
✅ Self-closing Tags must use a trailing slash (<br />, <hr />).

3. Key Differences Between HTML and XHTML

Feature	HTML	XHTML
Syntax	More flexible, allows errors	Strict, must follow XML rules
Tag Case	Not case-sensitive	Must use lowercase (`<title>`)
Closing Tags	Optional for some tags (`<p>`)	Mandatory (`<p></p>`)
Self-closing Tags	`<br>` or `<hr>` allowed	Must be written as `<br />`, `<hr />`
Attribute Values	Can be unquoted (`width=100`)	Must be quoted (`width="100"`)
Error Handling	Browsers auto-correct errors	Errors must be fixed manually

4. Why Use XHTML?

✅ Strict Code Validation: Helps developers write clean and well-structured code.
✅ Future-Proof: XHTML is based on XML, making it more compatible with future web technologies.
✅ Better Cross-Browser Compatibility: Ensures consistency across different web browsers.

When to Use XHTML?

When working with XML-based applications.
When strict code validation is required.
When ensuring compatibility with older mobile browsers.

5. Why Use HTML?

✅ Easier to Learn: More forgiving for beginners.
✅ Widely Used: Supported by all modern browsers.
✅ More Flexible: Can handle minor errors without breaking the page.

When to Use HTML?

When developing modern web applications.
When working with HTML5 features (XHTML is outdated in HTML5).
When focusing on speed and flexibility rather than strict syntax.

6. Which One Should You Use?

🚀 For modern web development, HTML5 is recommended because:

It supports new features like <video>, <audio>, and <canvas>.
Browsers no longer require XHTML’s strict syntax.
XHTML is no longer actively developed by the W3C (World Wide Web Consortium).

7. Summary

Feature	HTML (Recommended)	XHTML (Older Standard)
Flexibility	High (allows minor errors)	Strict (must follow XML rules)
Tag Case	Uppercase or lowercase	Must use lowercase
Closing Tags	Some tags can be left open	All tags must be closed
Self-Closing Tags	`<br>`, `<img>` allowed	Must use `<br />`, `<img />`
Best For	Modern web development (HTML5)	XML-based applications

🚀 Conclusion:

✅ Use HTML5 for modern web development.
✅ Use XHTML only if your project requires strict XML rules.
✅ XHTML has become outdated, while HTML continues to evolve.