Secondary Keywords: What They Are, How to Find Them and Where to Place Them

No page ranks for a single query. A guide that ranks for "standing desk" also appears for "sit stand desk", "standing desk benefits" and dozens of variants. Planning those secondary keywords on purpose is what turns a page that ranks for one term into a page that captures a whole topic. Google's own SEO Starter Guide asks site owners to think about the words a user might search for, noting that experts and newcomers often use different terms for the same thing. This guide shows how to find secondary keywords, where to place them and how many to use.

What are secondary keywords?

A secondary keyword is a search term related to the main keyword of a page, close enough in intent that the same page can answer it. For a page whose primary keyword is "standing desk", secondary keywords could be:

• Synonyms and close variants: "sit stand desk", "standing desks".
• Long-tail variants: "best standing desk for a small home office". See long-tail keyword.
• Subtopics: "standing desk height", "electric vs manual standing desk".
• Questions: "are standing desks good for your back".

The test is simple: if the person searching the secondary keyword would be satisfied by the page built for the primary keyword, it belongs on that page. If they would expect a different page, it is a separate primary keyword. For the full classification of keywords, see our guide to the types of keywords.

Primary vs secondary keywords: what is the difference?

The last line matters most. Two pages that target the same primary keyword compete with each other, a problem called keyword cannibalization. A secondary keyword never deserves its own page; if it does, it was a primary keyword all along.

Are LSI keywords and secondary keywords the same thing?

No. "LSI keywords" is a popular label for related terms, borrowed from latent semantic indexing, an information retrieval technique patented in 1988. There is no evidence Google uses it: in 2019, John Mueller of Google wrote that "there's no such thing as LSI keywords", as reported by Search Engine Roundtable. The useful idea behind the label survives: a page should use the vocabulary a knowledgeable author would naturally use. Our glossary explains the LSI keywords myth. Secondary keywords are a planning tool: real queries, with real demand, that you decide to cover.

How to find secondary keywords: 6 methods

1. Google Search Console

Open the Performance report, filter on the URL of the page and sort the queries by impressions. Queries with impressions but a weak position (beyond the first page) are secondary keywords Google already associates with the page: give each one a section or a sentence and the page often climbs.

2. People also ask and related searches

Search the primary keyword and expand the People also ask questions: each one is a candidate H3 or FAQ entry. Then read the related searches at the bottom of the page. Our guide to People also search for explains how to mine these boxes.

3. Google autocomplete

Type the primary keyword followed by a letter, a question word (how, why, which) or a qualifier (best, cheap, for). The suggestions reflect real searches.

4. The headings of the pages that rank

Open the top five results and list their H2 and H3 headings. Subtopics that all of them cover are the minimum your page needs; subtopics none of them covers are your chance to add something new.

5. A keyword tool and clustering

Export the variants of the primary keyword from a keyword tool, then group the terms whose search results overlap. Terms in the same group go on the same page as secondary keywords. Our guide to keyword clustering details the method, and our free keyword clustering tool does the grouping for you.

6. The sub-questions of AI assistants

Google states in its documentation on AI features that AI Overviews and AI Mode may use a query fan-out technique, running several related searches across subtopics. Ask ChatGPT or Gemini how it would answer the primary keyword and note the sub-questions it covers: they are secondary keywords for GEO.

Where to place secondary keywords

For the full checklist of on-page placements, see our guide to keyword optimization.

How many secondary keywords should a page have?

There is no official number. In practice, three to eight secondary keywords fit a 1,500-word article: one per H2 section, plus a few variants in the body. A long guide can cover more, a product page fewer. Two rules matter more than the count:

1. One section per sub-intent. If a secondary keyword deserves an explanation, give it a heading; if it is a synonym, use it once in the text.
2. No repetition for its own sake. Google's spam policies list keyword stuffing as a violation. There is no target keyword density; our free keyword density calculator helps you spot a term repeated far more than the others.

Example: a secondary keyword map for one article

Primary keyword: "standing desk". The plan below assigns each secondary keyword to a section, a method called keyword mapping:

Each section answers its secondary keyword in its first two sentences, so it can be read, ranked and quoted on its own.

Same page or separate page? The results overlap test

The hardest decision is whether a related term is a secondary keyword or deserves its own page. Search both terms in a private window and compare the first ten results:

• Many shared URLs (roughly half or more): Google treats the two queries as the same need. Cover the term as a secondary keyword.
• Few or no shared URLs: the intents differ. "Standing desk exercises" returns workout guides, not desk buying guides, so it needs its own page with its own primary keyword.
• Different formats: if one query shows product pages and the other shows guides, keep them apart even if the words look close.

Common mistakes with secondary keywords

1. Choosing terms by volume only. A popular term with a different intent pulls the page off topic and ranks nowhere.
2. Forcing exact phrases. "Standing desk best cheap" is how people type, not how people write. Use the natural form; Google matches the meaning.
3. Stacking all variants in one paragraph. Each secondary keyword belongs in the section that answers it.
4. Giving a secondary keyword its own thin page. Two weak pages split the signals that one complete page would gather.
5. Never revisiting the list. Search Console reveals new queries every month; a quarterly check adds the ones the page already attracts.

Secondary keywords for SEO and GEO

On Google, secondary keywords widen the set of queries a page ranks for and make its topic unambiguous. In AI answers, they play a second role: assistants split a question into sub-questions and look for passages that answer each one. A page whose sections each answer a precise secondary keyword offers exactly those passages. Covering the secondary keywords is covering the sub-questions, which is what makes a page complete for a reader and quotable for an AI.

Finding and mapping secondary keywords by hand takes time on every article. Sorank's automated keyword research finds the primary and secondary keywords of your site, and its blog article generator writes and publishes articles that cover them, with sources and internal links, in autopilot. Plans start at $49 per month on the annual plan, with a 3-day free trial.