Do your headings give the page a clear outline?
It checks missing main headings, distinct repeated main headings and gaps in the outline.
What Check Engine measures
Pages with readable content are checked for a missing main heading or multiple different main headings. Capitalisation and extra spaces are ignored when comparing heading text. A page with at least 300 words and no deeper subheadings can produce a missing-subheading finding. Using a third-level heading with no second-level heading produces a skipped-level notice. The check reads the heading markup. For example, a 300-word article with only a main heading can reach the missing-subheading finding.
The check reads headings and word counts on pages with usable content. Repeated copies of the same main-heading text receive different treatment from different main headings. Inspect the outline before changing shared headers.
How to read the result
Missing main headings are medium, multiple distinct main headings and absent subheadings low, and the skipped-level case a notice. A clean result does not establish that each heading accurately names its section.
Why it matters
Heading levels describe relationships between parts of a page. Visual styling alone does not provide that structure, so the check looks at actual markup rather than assuming large text is a main heading.
How to fix it
Give the page a clear main subject and use subheadings to divide substantial content where helpful. Keep levels in a sensible order and style them through CSS. Review repeated header furniture before removing an intentional content heading. Check the resulting outline as well as the rendered appearance after updating a template.
What we found in field audits
Problems in On-page SEO were found on 14 of the 14 sites we audited. These are area totals. Read the field-audit method.
Method note
backend/seo_engine/checks/onpage.py, headings, revision 0bb8e8d3.
Common questions
How much text can trigger the missing-subheading finding?
The test can apply from 300 words when deeper subheadings are absent. It reads markup rather than visual text size.
Are identical repeated main headings treated like different main headings?
No. Copies containing the same main-heading text are handled differently. Review the actual outline before removing template elements.
How serious is skipping straight to a third-level heading?
A third-level heading without a second-level heading can produce a skipped-level notice. Missing main headings have a separate result.