Introduction

The <!DOCTYPE html> tag is a required preamble for HTML documents. Here's how you use it.

Prerequisites

doctype illustration for: Prerequisites

Setting doctype in HTML5

To set the doctype in HTML5, add this to the top of your html code:

				
					
[label index.html]

&lt;!DOCTYPE html&gt;

				
			

Setting the doctype remains important for the support of legacy browsers.

Conclusion

Setting the doctype on your code is important, but it's only the first step. For a more comprehensive review of the HTML5 markup language, explore our series, How To Build a Website in HTML.