Header 3 tags, known as H3 Tags are meant to serve as sub headers to your page’s content.

They are the third largest & 3rd  boldest of all tags.

Search Engines do not limit the amount of H3 tags they will honor, and they are considered 5th highest in priority (after URL, Title Tag, H1 Tag & H2 Tag) for the keywords contained in them.

Search engines will honor the first 80 characters contained in each & traditionally the higher up on the page that a tag occurs the more value will be given to its keywords in terms of importance. 

The Importance Of H3 Tags & Search Engine Optimization

H3 tags are used to highlight bits of information that are not as important as H2 tags, but that are more important than site body content.

Typically, they are used for subheadings within an H2 tag’s body content block.

H3 tags are still viewed in higher importance than body content, making keyword research essential for the content placed within them.

Always ensure that H3 tags go along with the overall structure of your page’s theme, while adding more color & context to the URL, Title Tag, H1 & H2 tags’ keywords.