Semantic keywords are the words, phrases and concepts that belong to a topic: synonyms, subtopics, related entities and the questions people ask about it. A page on SOC 2 compliance naturally mentions auditors, Type I and Type II reports, controls and trust services criteria. Search engines that understand meaning use these signals to judge what a page covers and which queries it can answer.
Why they matter more than exact matches
Search systems map queries and pages to meanings rather than matching strings. A query like "how long does a SOC 2 audit take" can be answered by a page that never uses that exact phrase but discusses audit windows and observation periods. Covering the related concepts makes a page relevant to the many ways people phrase the same need.
The same applies to AI search. Systems that break a question into sub-queries look for passages that address each part, so a page that covers the surrounding concepts has more passages that fit.
How to find them
Group what you find into subtopics, then decide which belong on this page and which deserve their own page.
- Headings and subtopics on the pages that already rank
- People Also Ask questions and related searches
- Your own sales calls, support tickets and docs, which use customer language
- Entities connected to the topic: standards, tools, roles and processes
Using them well
Write sections that answer the related questions, rather than sprinkling words. If a term needs explaining, explain it. If it belongs to another page's topic, link there instead.
Example
A thin feature page that grew coverage
Hypothetical expense tool Ledgerfern had a page on receipt scanning that only repeated "receipt scanning app." The rewrite added sections on OCR accuracy for faded receipts, multi-currency handling, policy rules and accounting sync, each drawn from support questions. The page now matched far more of the ways buyers described the problem.
Common mistakes
Treating them as a checklist of words
The value comes from covering the ideas. A page that lists terms without substance is no more useful than before.
Cramming every subtopic onto one page
Some related topics deserve their own pages. Overloading one page blurs its focus and can create cannibalization later.
Questions
People often use them interchangeably, but "LSI" refers to a specific old technique Google does not use. "Semantic" or "related" terms is the more accurate description.
