HTML vs. XHTML: What’s the Difference?

HMTL and XHTML are similar but different technologies structure, and add formatting to web pages. So, what’s the difference between HTML and XHTML? Let’s look at some key elements that set these two technologies apart and their applications in today’s developing world.

Main Difference

HTML and XHTML are both markup languages used to create web pages. HTML is the standard markup language for creating web pages. XHTML is a newer version of HTML that is stricter and more well-defined.


HTML is easy to learn and use. It is not as strict as XHTML so it can be less frustrating for beginners. However, because HTML is not as well-defined, creating pages that look the same in all browsers can be more difficult.

XHTML is more difficult to learn than HTML, but it can be less frustrating for experienced developers. XHTML pages are likelier to look the same in all browsers because they must conform to stricter standards.


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Introduction To HTML

The Hypertext Markup Language (HTML) is the standard markup language for web pages. HTML tags allow you to add formatting and structure to text-based content. You may use HTML to create headers, paragraphs, lists, links, images, videos, audio, and other elements. HTML is the foundation of all websites.

Introduction To XHTML

XHTML stands for Extensible HyperText Markup Language. It is a language that describes how web pages should look and function. HTML (Hyper Text Markup Language) is the language that tells browsers what content goes where on a page.

XHTML is a subset of HTML that defines additional tags and attributes for describing the structure of documents. These tags allow web developers to create more complex web pages than those made using only HTML.

Differences Between HTML and XHTML

HTML is an application of Standard Generalized Markup Language (SGML), while XHTML is a reformulation of HTML 4.01 using XML 1.0. HTML and XHTML documents must conform to strict syntactic rules to be well-formed. Unlike HTML, XHTML requires all elements to be properly nested and all tags to be lowercase. Additionally, empty elements must be closed in XHTML (e.g.

1. Coding for Web Browsers: HTML vs. XHTML

When coding for web browsers, it is essential to understand the difference between HTML and XHTML. They may look similar, but they are pretty different. The main differences are that HTML does not require a declaration of encoding and has no strict formatting rules, while XHTML requires a declaration of encoding and strict formatting rules. The regulations behind each type can be found in the next blog post, Coding for Web Browsers: Understanding HMTL.

2. Understanding Structure: HTML vs. XHTML

Before diving into the nitty-gritty of HTML vs. XHTML, it’s essential to understand the basics of each markup language. HTML, or HyperText Markup Language, is a standard language for structuring web content. Meanwhile, XHTML, or Extensible HyperText Markup Language, is a version of HTML that adheres to stricter XML rules.

3. Creating Structured Documents: HTML vs. XHTML

The main difference between HTML and XHTML is that XHTML requires all elements to be correctly nested within each other. Another difference is that all tags in XHTML must be lowercase. Lastly, empty elements must be closed in XHTML using a trailing slash.

4. Choosing Between HTML and XHTML

When it comes to HTML and XHTML, there are a few key differences that you should be aware of. HTML is the standard markup language for most web pages, while XHTML is a stricter, more well-defined version of HTML. Additionally, HTML5 is the latest version of HTML, while XHTML 1.0 is the latest version of XHTML. So, if you’re looking for maximum compatibility and flexibility, you should go with HTML.

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Key Differences Between HTML vs XHTML

  1. HTML stands for Hypertext Markup Language. HTML is what web browsers use to display websites. HTML tags tell the browser how to format text and images on a page. HTML was initially designed for documents on the World Wide Web, but it can also be used to create static pages.
  2. XHTML stands for Extensible HyperText Markup Language. XHTML is an updated version of HTML that adds additional functionality to HTML. XHTML is backward compatible with HTML 4.01, meaning that any valid XHTML document is also a valid HTML document.
  3. Both HTML and XHTML are markup languages. A markup language is a set of rules that tells a computer program how to format information.
  4. HTML is not case-sensitive. XHTML is case sensitive. Case sensitivity refers to whether letters have different meanings depending on their position in words. For example, “a” and “A” both mean “alpha” in English, but they have different meanings in programming. In HTML, “a’s” and “a” are equivalent. In XHTML, “a’s” and ‘a’ are not equivalent.
  5. HTML is a subset of XML. XML (Extensible Markup Language) is a way to mark up data. XML is commonly used to store data in databases.
  6. HTML is a type of SGML (Standard Generalized Markup Language). SGML is a standard for writing structured documents. HTML is a specific kind of SGML.
  7. HTML is a scripting language. Scripting languages allow programmers to write programs without knowing how to code. JavaScript is a popular scripting language.
  8. HTML is a client-side language. Client-side means that it runs on the user’s computer. When a website loads, the browser sends requests to the server asking for files. The server then sends back the requested file. Client-side languages run on the user s computer before the browser receives the request.
  9. HTML is a tag-based language. Tag-based means that a particular tag surrounds each piece of content on a webpage. Tags make it easier to organize content on a page.
  10. HTML is a verbose language. Verbose means that it uses many words to describe something simple. HTML is a verboseness because it contains lots of tags. Each tag has its name and description.
  11. HTML is a declarative language. Declarative means describing what should happen instead of telling the computer how to do it. HTML is decorative because it tells the browser how to lay out the page.
  12. HTML is a procedural language. Procedural means that it tells the computer exactly what to do. HTML is procedural because it tells the browser exactly where to put things.
  13. HTML is a dynamic language. Dynamic means that it changes based on the situation. HTML is dynamicity because it varies depending on the browser.
  14. HTML is a weakly typed language. Weakly typed means that it doesn’t require types to be specified. HTML is a weakness because it doesn’t specify the type of data.


In conclusion, there are a few critical differences between HTML and XHTML. For one, XHTML is more strict than HTML and must be well-formed. All tags must be nested appropriately, and all attributes must be quoted. Additionally, XHTML requires all tags to be lowercase and all attributes to use only values – never variables. Finally, empty elements in XHTML must permanently be closed with a trailing slash.