What is the Difference Between HTML and XHTML?
🆚 Go to Comparative Table 🆚The main difference between HTML and XHTML lies in their syntax and structure. HTML (Hypertext Markup Language) is more lenient in its syntax, while XHTML (Extensible Hypertext Markup Language) has a more strict syntax and follows XML rules. Here are some key differences between the two:
- SGML-based vs. XML-based: HTML is based on Standard Generalized Markup Language (SGML), while XHTML is an XML-based language.
- Case-sensitivity: HTML is not case-sensitive, but XHTML is case-sensitive, meaning that tags and attributes must be written in lowercase.
- Empty elements: In HTML, empty elements do not require a closing tag or a "/" symbol to signify the end of the tag. In XHTML, empty elements must always be closed, with a "/" symbol at the end of the empty element.
- Strict error handling: XHTML has stricter error handling compared to HTML. Browsers may ignore errors in HTML pages and try to display the website even if there are some errors in the markup. In contrast, XHTML has more strict error handling, and some older web browsers may not be able to display XHTML documents properly.
- Backward compatibility: XHTML is not backward compatible with older versions of HTML, meaning that some older web browsers may not be able to display XHTML documents properly.
In summary, HTML and XHTML are both markup languages used for creating web pages, but they have different syntax rules and structures. XHTML is a stricter, more XML-based version of HTML, making it more suitable for future technologies and advancements.
Comparative Table: HTML vs XHTML
Here is a table comparing the differences between HTML and XHTML:
| Feature | HTML | XHTML |
|---|---|---|
| Definition | HTML is the standard markup language for creating web pages. | XHTML is a stricter, more XML-based version of HTML. |
| Extensibility | HTML is not XML-based, making it less extensible and flexible. | XHTML is HTML defined as an XML application, making it more extensible and flexible. |
| Error Handling | Browsers ignore errors in HTML pages, attempting to display the website even if there are some errors in the markup. | XHTML has stricter error handling, requiring elements to be well-formed and error-free. |
| Elements | HTML may have some optional elements. | XHTML requires all elements to be properly nested and closed. |
| Case Sensitivity | HTML is not case-sensitive. Attribute names can be written in any case. | XHTML is case-sensitive. Attribute names must always be in lowercase. |
| xmlns Attribute | HTML does not require the xmlns attribute in the element. | XHTML requires the xmlns attribute in the element. |
Both HTML and XHTML are used to create web pages and applications, but they have some key differences that set them apart. XHTML is an extended version of HTML, which makes it more strict and standardized. It is also an XML-based language, making it more extensible and flexible than HTML.