Heading Structure

Subheadings used to be made by enlarging text. Bold a line, bump it up two sizes, and it looks like a heading on screen, which seems like enough. To a human eye it is.

The trouble is that people aren't the only readers. Large bold text is just text to a machine. A 3,000-word article with eight bold lines and no heading tags gives a search engine no way to know the piece divides into eight topics, and twenty paragraphs get read as one block.

People who read differently hit the same wall. A screen reader, the software that reads a screen aloud, can pull headings out into a list to jump between, and with no tags that list is empty. Heading structure is the work of recording the hierarchy where a machine can read it, independently of the sizes anyone sees.

Heading tags run h1 through h6, with the lower number being the larger heading. Five things to hold.

1. Exactly one h1 per page, the article title at the top of the body. It's a different value from the title tag that appears as the blue link in search results.
2. Don't skip levels. Going from h2 straight to h4 reads as though a layer went missing in between.
3. Choose by hierarchy, not by size. Don't switch an h2 to an h4 to make it look smaller. Set the visual size separately and match the tag to the layer of the content.
4. Put the section's content into the subheading. "Other" and "Learn more" give no way to tell where they lead, even in a generated table of contents.
5. Go three levels deep at most. Below h4 readers lose track of which layer they're in.

There's one more thing you get. The featured snippet, the extracted answer shown at the top of search results, usually takes a subheading and the paragraph directly under it. Phrase a subheading as a question and answer it in two sentences underneath and the odds of being picked go up.

Hierarchy alone won't raise a ranking, though. The depth of content that satisfies the search intent is content quality, and the skeleton only pays off when that content exists.

"There are no heading tags in this article. Just eight bold lines."

The structure exists only for human eyes.

"It goes h2 then h4. A level got skipped."

The hierarchy is broken and the tags need fixing.

"Let's rewrite the subheadings as questions. That's the slot that gets extracted."

Reshaping the format to aim at the snippet position.

Noa wrote these rules into a document while tidying up formatting on the Pagedeck blog: one h1 for the article title, h2 for sections, and h3 for branches inside a section, with nothing deeper. Two of the six articles Ravi wrote afterwards landed in the extracted answer slot.