Keyphrase in subheading: what Yoast counts and when to ignore it

What counts as a heading that reflects the topic

Yoast calls H2 and H3 your "higher-level subheadings" and ignores H4 to H6. For languages with function word support, a heading counts as reflecting the topic when at least half of the keyphrase's content words appear in it. For other languages, all content words must appear.

That half rule is more forgiving than it sounds. With the keyphrase sourdough starter, a heading like "Signs your starter is ready" already counts, because starter is one of two content words. Synonyms added in Yoast SEO Premium count too.

The outcomes, in Yoast's own words:

• Too few: "Use more keyphrases or synonyms in your higher-level subheadings!"
• Too many: "More than 75% of your higher-level subheadings reflect the topic of your copy. That's too much. Don't over-optimize!"
• One subheading only, and it matches: green.
• No subheadings at all in a text over 300 words (250 for cornerstone content): red. Under that length, Yoast says the text "is short enough and probably doesn't need them."

Why headings became a keyword target

Headings are the outline of a document. Early SEO advice treated them as weighted text: words in an h1 or h2 were assumed to count for more than words in a paragraph, so writers packed them with keywords. Yoast's check keeps a softer version of that idea, and adds the upper cap specifically to discourage the old habit of repeating the keyword in every heading.

The better argument for the check is human. Readers skim headings to decide whether a page covers their question, and screen reader users often move through a page heading by heading. If none of your headings mention the subject, the outline does not tell either group what the page is about.

How much headings matter to Google

Google uses headings as one way to understand the structure of a page and what each section covers. That is different from saying a keyword in an H2 moves rankings. Google matches pages to queries using the whole content, synonyms and context, so a section called "Feeding schedule" can be understood as part of a sourdough page without repeating the word.

What does hurt is the pattern the 75 percent cap is aiming at: headings that repeat the same phrase with trivial changes. They read as written for a machine, make the outline useless, and can look like keyword stuffing if they are extreme.

Editing headings without forcing the phrase

Treat a red result as a prompt to reread your outline:

1. List your H2s and H3s on their own. Do they describe the sections, or are some just "Introduction", "More tips" and "Conclusion"?
2. Replace generic headings with specific ones. "More tips" becomes "Keeping a starter alive while you travel".
3. Let the topic word appear where it fits naturally, typically in two or three headings, not all of them.
4. Check the level. A heading that should be an H2 but was set as H4 for its font size is invisible to this check and confuses the outline; fix the level and style it separately.

Leave the check red when the page's structure genuinely does not call for the keyphrase: a product roundup where each H2 is a product name, a FAQ page where each heading is a question in the reader's words, or a timeline with a year per heading. Forcing the keyphrase into those makes the page harder to use.

Headings in Hydrogen SEO

Hydrogen SEO's per-post SEO score does not grade headings or keyword placement in them. Heading structure is covered site-wide instead: the Content structure area of the site health score looks for sensible heading hierarchies and scannable sections across your pages. For the structural side, see heading hierarchy skipped.