What is XHTML (Extensible Hypertext Markup Language)?

XHTML (Extensible Hypertext Markup Language) is a markup language that combines the flexibility of HTML with the stricter syntax rules of XML. In this article, we will explore the concept of XHTML, its key features, benefits, and its role in creating structured and interoperable web content. From understanding its syntax to exploring its compatibility, let’s delve into the world of XHTML.

What is XHTML?

XHTML (Extensible Hypertext Markup Language) is a markup language that follows the rules of XML, combining the elements of HTML with the stricter syntax and structure requirements of XML.

Key Features of XHTML

  • XML Syntax: XHTML adheres to XML syntax rules, requiring well-formed and properly closed tags.
  • Document Structure: XHTML enforces a hierarchical structure similar to HTML, defining elements and their relationships.
  • Extensibility: XHTML allows the creation of custom tags and the use of namespaces to extend its functionality.

Syntax and Structure of XHTML

  • XHTML Document Declaration: XHTML documents begin with a declaration specifying the version of XHTML being used.
  • Opening and Closing Tags: XHTML uses opening and closing tags to enclose elements, following the XML syntax.
  • Attribute Values: Attribute values must be enclosed in quotes and must adhere to XML rules for escaping special characters.

Benefits of XHTML

  • Structure and Consistency: XHTML enforces a stricter structure and syntax, promoting consistency and adherence to web standards.
  • Compatibility with XML: XHTML’s adherence to XML rules allows for seamless integration with XML-based technologies and data interchange.
  • Device and Platform Independence: XHTML’s structured nature ensures compatibility across different devices and platforms, enhancing interoperability.
  • Accessibility and Search Engine Optimization: XHTML’s cleaner syntax and structured approach contribute to better accessibility for users and improved search engine indexing.
  • Future-Proofing: XHTML paves the way for evolving web standards and compatibility with emerging technologies.


  • HTML5 as an Evolution: HTML5 incorporates many features and benefits of XHTML, such as the stricter syntax and improved structure.
  • XHTML5: XHTML in HTML5: XHTML5 is the XHTML representation of HTML5, allowing developers to use XHTML syntax while benefiting from HTML5’s features.


XHTML (Extensible Hypertext Markup Language) bridges the gap between HTML and XML, offering a structured and interoperable approach to web content creation. With its stricter syntax, well-formedness requirements, and compatibility with XML, XHTML promotes consistency, accessibility, and future-proofing.

Although HTML5 has absorbed many XHTML principles, understanding XHTML’s syntax and benefits remains valuable for developers seeking structured and interoperable web content.

By embracing XHTML, web developers can create robust, compliant, and accessible websites that adapt to evolving web standards and facilitate seamless integration with XML-based technologies.