There are six levels of heading elements in HTML5: h1..h6 where h1 is rendered as the largest font and the seccessive ones are rendered relatively smaller to each other. Here is an example showing all headings in HTML5:

			<!DOCTTYPE html> 
<!--Example 2: Headings.html -->
<title> Headings example </title>
<h1>This is level-1 </h1>
<h2>This is level-2 </h2>
<h3>This is level-3 </h3>
<h4>This is level-4 </h4>
<h5>This is level-5 </h5>
<h6>This is level-6 </h6>
Here is the rendered HTML5 document:

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Date of last modification: 2020.