You want to view your document’s content outline.

Run your page through the HTML5 Outliner tool: http://gsnedders.html5.org/outliner/.

HTML5 has an outline algorithm that calculates the structure of a web document. This algorithm is based on sections defined by the new structural elements.

For the main document outline, section and aside each introduce a new section in the outline, while the heading(s) within each form the outline content. This is known as explicit sectioning.

Let’s examine the following markup example:

<section>
    <h1>Most Recent Blog Posts</h1>
    <article>
        <h2><code>nav</code> Isn't for <em>All</em> Links</h2>
        <p>Though the <code>nav</code> element often contains links, that doesn't
           mean that <em>all</em> links on a site need <code>nav</code>.</p>
    </article>
    <article>
        <h2>You've Got the <code>DOCTYPE</code>. Now What?</h2>
        <p>HTML5 isn't an all or nothing proposition. You can pick and choose what
           works best for you. So once you have the <code>DOCTYPE</code> in place,
           you should explore.</p>
    </article>
</section>