The <h1> to <h6> elements are used to define six levels of HTML Headings, with <h1> being the highest (or most important) level and <h6> the least important one.
Each web page must have only one <h1> heading. As search engines use it to index the structure and content of web documentst, be sure to include keywords in it.
The <h1>-<h6> tags come in pairs, so the closing tag is required.
As the <h1> to <h6> tags are block-level elements, they always start on a new line and take up the full width available.
<html> <head> <title>Title of the document</title> </head> <body> <h1>First-level heading</h1> <h2>Second-level heading</h2> <h3>Third-level heading</h3> <h4>Fourth-level heading</h4> <h5>Fifth-level heading</h5> <h6>Sixth-level heading</h6> </body> </html>
The <h1>-<h6> elements must not be used to markup subheadings, subtitles, alternative titles and taglines unless intended to be the heading for a new section or subsection.
|Defines the vertical alignment of the tag content.
Not supported in HTML 5.