HTML DOCTYPE Declaration

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:

<!DOCTYPE html>

Browser Support

ElementChromeInternet explorerMozilla FirefoxSafariOpera

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" "">

XHTML 1.1:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "">

Example for HTML Doctype Declaration:

<!DOCTYPE html>
<title>Title of the document</title>

The content of the document......