W3Schools.com

HTML Doctypes

A doctype declaration refers to the rules for the markup language, so that the browsers render the content correctly.

Example

An HTML document with a doctype of HTML 4.01 Transitional:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Title of the document</title>
</head>

<body>
The content of the document......
</body>

</html>

HTML Different Doctypes

The doctype declaration is not an HTML tag; it is an instruction to the web browser about what version of the markup language the page is written in.

The doctype declaration refers to a Document Type Definition (DTD). The DTD specifies the rules for the markup language, so that the browsers render the content correctly.

The doctype declaration should be the very first thing in an HTML document, before the <html> tag.

Remark Tip: Always add a doctype to your pages. This helps the browsers to render the page correctly!

HTML 4.01 Strict

This DTD contains all HTML elements and attributes, but does NOT INCLUDE presentational or deprecated elements (like font and center). Framesets are not allowed:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">

HTML 4.01 Transitional

This DTD contains all HTML elements and attributes, INCLUDING presentational and deprecated elements (like font). Framesets are not allowed:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">

HTML 4.01 Frameset

This DTD is equal to HTML 4.01 Transitional, but allows the use of frameset content:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Frameset//EN"
"http://www.w3.org/TR/html4/frameset.dtd">

Tips and Notes

Look at our table of all HTML/XHTML elements, and which DTD each element appears in.

Use W3C's Validator to check that you have written a valid HTML/XHTML document!

HTML DOCTYPE Element

Tag Description
<!DOCTYPE> Defines the document type. This declaration goes before the <html> start tag


WEB HOSTING
Best Web Hosting
PHP MySQL Hosting
Best Hosting Coupons
UK Reseller Hosting
Cloud Hosting
Top Web Hosting
$7.95/mo SEO Hosting
Premium Website Design
WEB BUILDING
XML Editor - Free Trial!
FREE Website BUILDER
Free Website Templates Free CSS Templates
Make Your Own Website
W3SCHOOLS EXAMS
Get Certified in:
HTML, CSS, JavaScript, XML, PHP, and ASP
W3SCHOOLS BOOKS
New Books:
HTML, CSS
JavaScript, and Ajax
STATISTICS
Browser Statistics
Browser OS
Browser Display
SHARE THIS PAGE