This section identifies pages with missing or multiple H1 tags.
H1 tags are HTML heading tags used to denote the header of the page’s content (or as a section header if your site uses HTML5), functioning as the title of the content (note: this is not the same thing as the page title, although they should usually be very similar). H1 tags appear in the <body> tag of your page:
<h1>The Title of Your Page’s Content</h1>
Like title tags, search engines see them as descriptions of a page’s content and heavily rely on them when determining pertinence to a search query. Search engines will struggle to interpret content without an H1 tag to help them, while including your page’s keyword will help them connect it to relevant search queries. Unlike meta tags, there are no ideal character counts or limits.
Using multiple H1 tags on a page is an old black hat tactic, so if your page doesn’t use HTML5, or if you’re not sure, only use one H1 tag per page.