What Are LSI Keywords in SEO? The Myth and What Actually Works
Why "LSI keywords" is a myth, and what to do instead: cover related topics and terms that readers expect.
"Add LSI keywords to rank higher" is common SEO advice. LSI stands for latent semantic indexing, an information retrieval technique from the late 1980s. Google has said it does not use LSI, and the term "LSI keywords" is a marketing label rather than a real ranking concept. But the idea behind the advice โ covering related terms and topics โ does matter.
Where the myth comes from
LSI was designed to find relationships between words in small, fixed sets of documents. The web is vast and constantly changing, and modern search engines use far more advanced language understanding. Tools that sell "LSI keyword lists" usually just show related words or phrases that appear on top-ranking pages.
What actually helps
Search engines understand topics, entities and the relationships between them. A page that covers a subject thoroughly naturally uses the vocabulary people expect. For a page about making filter coffee, that might include decoction, filter, chicory, frothing, steel tumbler and dabarah โ not because they are "LSI keywords", but because a good answer needs them.
How to find related terms and topics
- People also ask and related searches in Google.
- Headings of top-ranking pages โ which subtopics do they all cover?
- Customer questions โ the words real people use.
- Your own expertise โ the terms a professional would naturally explain.
Read how to find content gaps for a structured method.
How to use them naturally
- Cover the subtopics as sections, not as scattered words.
- Explain technical terms the first time you use them.
- Use synonyms and variations instead of repeating one phrase.
- Never paste lists of related words into a page โ that is keyword stuffing. See what keyword stuffing is.
Check your coverage
The free keyword density checker shows the main words and phrases your page uses, so you can see whether important related terms are missing โ or whether one phrase dominates. For subtopic coverage, use the topical coverage calculator.
A worked example
A blog post on "how to choose a laptop for students" ranked on page three. A keyword list from an "LSI tool" suggested adding words like "laptop price" and "best laptop" throughout. Instead, the author compared the page with top results and added sections on battery life, weight, RAM for coding courses, warranty and student discounts โ the real questions buyers ask. The page reached the first page within two months, using many related terms naturally.
A simple related-terms exercise
Before writing, spend ten minutes on this:
- Write down the main question your page answers.
- List every sub-question a beginner would ask next.
- List the technical terms an expert would use when answering.
- Check People also ask for questions you missed.
- Turn the strongest sub-questions into H2 or H3 headings.
This gives you a natural outline that covers the topic properly. The related vocabulary then appears on its own, because you cannot explain those sub-questions without it.
Related guides
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Frequently asked questions
Does Google use LSI keywords?
No. Google has said it does not use latent semantic indexing.
Are related keywords still useful?
Yes. Covering related topics and using natural vocabulary helps pages answer searches completely.
Should I buy an LSI keyword tool?
Not for the LSI label. Free sources like People also ask and top results show related terms well.
How many related keywords should I add?
There is no number. Cover the subtopics a reader needs; the right words follow naturally.