HTML <!DOCTYPE> Declaration
Example
<!DOCTYPE html>
<html>
<head>
<title>Title of the document</title>
</head>
<body>
The content of the document......
</body>
</html>
Try it Yourself »
Definition and Usage
All HTML documents must start with a <!DOCTYPE> declaration.
The declaration is not an HTML tag. It is an "information" to the browser about what document type to expect.
In HTML 5, the declaration is simple:
<!DOCTYPE html>
Browser Support
| Element | |||||
|---|---|---|---|---|---|
| <!DOCTYPE> | Yes | Yes | Yes | Yes | Yes |
Older HTML Documents
In older documents (HTML 4 or XHTML), the declaration is more complicated because the declaration must refer to a DTD (Document Type Definition).
HTML 4.01:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
XHTML 1.1:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
HTML Elements and Doctypes
Look at our table of all HTML elements, and what Doctype each element appears in.
Tips and Notes
Tip: The <!DOCTYPE> declaration is NOT case sensitive.
Examples
<!DOCTYPE html>
<!DocType html>
<!Doctype html>
<!doctype html>
