Keyword synonyms and word forms

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People search for the same thing in different words. A recipe for "mango pickle" may also be called "aam achar", and a page about "running shoe" naturally says "running shoes". Without synonyms, the keyword checks only look for the exact phrase, so natural writing can fail them.

With RankFlect SEO Pro you can give each focus keyword a list of synonyms. The keyword checks then pass when you use the keyword, one of its synonyms or, on English sites, a simple word form of either.

Add synonyms

1. Open the post and the General section of the RankFlect SEO panel (in the Classic Editor, the RankFlect SEO box).
2. Add your focus keywords.
3. Under them, the Synonyms field has one box per keyword, such as "Synonyms for “mango pickle”, comma separated". Type the synonyms, separated by commas.
4. Save the post.

The hint under the field reads: "The keyword checks also count these synonyms and, for English, word forms such as plurals and -ed or -ing."

Each keyword has its own synonyms. If you remove a keyword, its synonyms are no longer used.

What counts

A keyword check passes when the text contains any of these:

• The focus keyword itself.
• One of its synonyms.
• On English sites, a word form of the keyword or a synonym.

Word forms change only the last word of the phrase:

Form	Example
Plural with -s	"running shoe" → "running shoes"
Plural with -es	"lunch box" → "lunch boxes"
Plural with -ies	"summer party" → "summer parties"
-ed	"pickle" → "pickled"
-ing	"pickle" → "pickling"

It also works the other way: the keyword "running shoes" matches "running shoe". The forms are kept simple on purpose, and a word form only counts as a whole word. Word forms are not added for other languages, but synonyms work in every language.

Which checks use synonyms

These checks count synonyms and word forms:

• Focus keyword appears in the SEO title.
• Focus keyword is near the start of the title.
• Focus keyword appears in the meta description.
• Focus keyword appears in the URL slug.
• Focus keyword appears in the first paragraph.
• Focus keyword appears in a subheading.
• Keyword density: every use of the keyword, a synonym or a word form adds up to one count.

Each related keyword uses its own synonyms for its own score. See Content analysis checks.

Tip Synonyms help the checks match how you really write. They don't change what is printed on the page, and they don't need to appear on the page themselves.

Synonyms for AI agents

Over MCP, get_focus_keywords also returns the synonyms of each keyword on Pro. set_focus_keywords takes an optional synonyms object, for example {"mango pickle": ["mango achar", "aam achar"]}. The list you give replaces that keyword's synonyms, an empty list removes them, and keywords you leave out keep theirs. The change is written to the Change Log like any other. See MCP tools reference.

On the free plan

The free plan has one focus keyword, and the checks look only for the keyword itself. The hint under the keyword field links to Add unlimited related keywords, synonyms and word forms with Pro.

FAQ

Do synonyms count as extra focus keywords?

No. A synonym belongs to one keyword and helps that keyword's checks pass. To score another phrase on its own, add it as a related keyword.

Why doesn't "mice" match "mouse"?

Word forms only cover regular endings: -s, -es, -ies, -ed and -ing. Add irregular forms such as "mice" as synonyms.

Will synonyms make keyword stuffing look fine?

No. Keyword density counts the keyword, synonyms and word forms together, so using many synonyms still raises the density. Aim for 0.5–2.5%.