HTML vs XHTML

HTML and XHTML can describe similar web pages. Their main difference is the syntax and parser they use.

What Is the Difference Between HTML and XHTML?

Quick Answer

HTML uses HTML syntax and defined error-recovery rules. XHTML uses XML syntax, so every element must be nested and closed correctly. The response's MIME type tells the browser which parser to use.

Why Use HTML vs XHTML?

Example 1: HTML Syntax

HTML allows the short boolean attribute checked. Void elements such as <br> do not use closing tags. 

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>HTML Example</title>
</head>
<body>
    <h1>Course Status</h1>
    <label>
        <input type="checkbox" checked>
        Ready to learn
    </label>
    <br>
</body>
</html>

What Are HTML and XHTML?

HTML means HyperText Markup Language. Web servers normally send HTML as text/html. The browser then uses its HTML parser.

XHTML means Extensible HyperText Markup Language. It is HTML written with XML syntax. True XHTML is usually sent as application/xhtml+xml, which makes the browser use an XML parser.

Key Differences Between HTML and XHTML

HTML and XHTML syntax comparison
Rule HTML XHTML
MIME type text/html application/xhtml+xml
Parser HTML parser XML parser
Element names Not case-sensitive in HTML syntax Case-sensitive; HTML names use lowercase
Closing elements Some end tags can be omitted Every element must close correctly
Attribute values Some quotes can be omitted Every value must be quoted
Nesting Parser can repair some mistakes All elements must be nested correctly
Syntax errors Uses defined recovery rules A well-formedness error stops normal parsing

How Browsers Process HTML and XHTML

A file's code alone does not choose the parser. For a web response, the MIME type controls how the browser reads the document.

HTML and XHTML parser comparison HTML sent as text/html uses the HTML parser and error recovery. XHTML sent as application/xhtml+xml uses the XML parser and requires well-formed markup. The MIME Type Selects the Parser HTML Response text/html HTML Parser Applies error recovery XHTML Response application/xhtml+xml XML Parser Requires well-formed XML
HTML and XHTML use different parsers and error-handling rules.

Example 2: XHTML Syntax

XHTML writes an explicit value for checked and closes every empty element with XML syntax. The root element declares the XHTML namespace. 

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" lang="en">
<head>
    <meta charset="UTF-8" />
    <title>XHTML Example</title>
</head>
<body>
    <h1>Course Status</h1>
    <label>
        <input type="checkbox" checked="checked" />
        Ready to learn
    </label>
    <br />
</body>
</html>

Should You Use HTML or XHTML?

Use modern HTML for most websites. It has wide browser support and is easier for beginners. Use XHTML only when a project specifically needs XML tools or XML processing.

Clean habits still matter in HTML. Use lowercase element names, quote attribute values, nest elements correctly, and close normal elements.

Common Comparison Mistakes

Practice

Practical 1: Run a HTML vs XHTML example

Output: The browser preview renders the HTML code above.

Explanation: This runnable example demonstrates HTML vs XHTML in a complete HTML preview.

What You Learn: You practice the correct HTML structure used for HTML vs XHTML.

Practical 2: Run a HTML vs XHTML example

Frequently Asked Questions

What is the main difference between HTML and XHTML?

HTML uses HTML syntax and an HTML parser. XHTML uses XML syntax and an XML parser, so its markup must be well-formed.

Is XHTML the same as HTML?

No. They can describe similar web content, but their syntax and parsing rules are different.