XHTML Tutorial

This XHTML tutorial demonstrates how to code web pages using XHTML. It assumes that you're already comfortable with HTML. XHTML is almost identical to HTML with only a handful of differences. XHTML is slightly more strict than HTML and requires a little more attention when coding.

XHTML was developed by the W3C to help web developers make the transition from HTML to XML. So if you want to learn XML, XHTML is a good place to start.

Here are the main things to remember when writing XHTML:

Here's a more detailed explanation of the above XHTML rules.

The Root Element

The root element of the document must be html. Read more about the <html> element.

The xmlns Declaration

All XHTML documents must have an xmlns declaration for the XHTML namespace (i.e. http://www.w3.org/1999/xhtml). Read more about the HTML xmlns declaration.

Example:

DOCTYPE

All XHTML documents must have a DOCTYPE declaration. The document must include the usual html, head, title, and body elements.

Example:

Case

All XHTML tags should be lower case. (HTML tags on the other hand, can be upper or lower case).

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Closing tags

All tags should have an opening tag and a closing tag. If it's a tag that doesn't have a closing tag (for example, the img tag, or the hr tag, use a space and forward slash (/) before the > sign. (Note that the XHTML specification does not require a space before the "/" but this is required to conform with some browsers).

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Quotes

In XHTML, all attribute values must be quoted. (In HTML on the other hand, you could get away without quoting attribute values).

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Minimization

Minimization is forbidden. You should explicitly state the attribute and the value.

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The id attribute

The id attribute replaces the name attribute. Instead of using name=,use id=.

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Script tag

The language attribute of the script tag is deprecated.

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Nesting

All tags must be nested properly.

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Apart from these strict rules, you can code your XHTML pages just like you've been coding HTML pages. To learn more about coding HTML, check out the HTML tutorial.

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