Why heading structure matters
Headings are the table of contents of a page. People skim them to decide whether to read. Screen reader users jump between them. Search engines and AI systems use them to work out what each section covers, which is how a single section of a long page can answer a specific question. A clean outline doesn’t guarantee rankings, but a messy one makes every one of those jobs harder.
What we flag and why
- No H1. The page has no top-level statement of what it’s about. Usually the visible page title is styled text instead of an
<h1>. - Several H1s. Allowed, but often accidental: a logo, a hero slogan and the real title all marked as H1.
- Skipped levels. An H2 followed by an H4. Usually a heading chosen for its font size rather than its place in the outline.
- Empty headings. Icon-only headings or leftover template tags. They add noise to the outline and to screen readers.
- Very long headings. Over 120 characters is almost always a paragraph styled as a heading.
A good outline, in practice
- One H1 that says what the page is, in the words people search for.
- H2s for the main sections. Write them as the questions or tasks the reader has.
- H3s only inside an H2, for sub-steps or options.
- Style with CSS. Pick the tag for the structure, never for the size.
Section headings phrased as questions pair well with an FAQ block. Draft one from your outline with the AI FAQ generator, and check the title and meta description with the meta tag checker.
Limits
We read the first 2 MB of HTML, list up to 400 headings, and don’t run JavaScript or CSS. Headings inside hidden menus or tabs show up here even if they’re not visible, and headings injected by a script don’t.