LSI Keywords

LSI stands for Latent Semantic Indexing, an old maths technique from information retrieval. It was never a Google SEO feature. Yet many blog posts still tell you to find a list of 'LSI keywords' for each target keyword and sprinkle them into your content. I think that advice is worse than useless: it leads you to stuff your page with unnatural terms, and it misses the real point.

The real point is that Google wants to understand what your page is about by looking at the words around your main topic. If you write a page about 'coffee', it will see words like 'brew', 'roast', 'beans', 'caffeine', 'mug'. Those are not synonyms; they are contextually related terms that help define the subject. That is what people mean when they say 'LSI keywords' – but the label is misleading.

I prefer to think of it as building topical relevance. When I write a page, I ask: what subtopics does someone searching for this term also care about? I check the [SERP](/serp/) for related searches at the bottom, and I look at the [People Also Ask](/people-also-ask/) box. Those give me the actual terms users and Google associate with the topic. I work them into headings, subheadings, and naturally into the body where they add value.

So the plain-English take: stop treating LSI keywords as a secret list. Treat them as a reminder to cover your topic thoroughly and naturally.

Thinking about related terms matters most when you are writing a new page or rewriting an old one that is not performing. If your page ranks but gets few clicks, or if it ranks for the main term but not for related queries, you probably missed some subtopics.

I recently revisited a page about [keyword research](/keyword-research/). The original version only used the phrase 'keyword research' and a few synonyms. It ranked okay but didn't appear for 'search volume', 'keyword difficulty', or 'search intent'. I added sections covering those naturally, using the terms where they fit. Within a month, that page picked up more impressions and started showing in People Also Ask boxes.

It matters when your competitor pages are more comprehensive. Check the top 3 results for your target [keyword](/keyword/). What terms do they use that you don't? Are they covering [long-tail keywords](/long-tail-keywords/) or [intent SEO](/intent-seo/) angles that you missed? The goal is not to copy them, but to see which terms naturally belong in the topic.

It also matters for entity recognition. Google's Knowledge Graph links entities together. If your page mentions 'grinding', 'extraction', 'espresso', it helps Google connect your page to the broader topic of coffee. That can improve your relevance for related searches.

But be careful: forcing terms into every paragraph makes your copy stiff. I only add a term if it fits the flow and answers a real question. If it feels forced, I leave it out. The benefit of natural language outweighs the theoretical value of including every related term.

I used to believe that 'LSI keywords' were a secret Google ranking factor. I spent hours in keyword tools filtering for 'LSI' scores and lists. I would add those terms into my content even if they made no sense in context. I remember a page about 'baking soda' where I forced in 'sodium bicarbonate' and 'baking powder' because the tool said they were related. That page performed terribly.

What I got wrong was thinking that Google used a technique called Latent Semantic Indexing for ranking. Google has repeatedly said it does not. I also confused correlation with causation: just because top-ranking pages share certain terms, doesn't mean adding those terms will make me rank. Top pages rank because they are authoritative and comprehensive, not because they contain a checklist of words.

I also underestimated the role of search intent. I used to dump related terms into a page without considering whether the user actually wanted that information. Now I start with [keyword analysis for SEO](/keyword-analysis-for-seo/) to match intent, then build content around the questions real people ask.

Today I no longer use the phrase 'LSI keywords' in my work. I talk about topical coverage, semantic relevance, and natural language. The change improved my writing and my results. If you are still chasing LSI keyword lists, I recommend you stop and look at the SERP instead.