What Are Semantic Keywords? (And Why LSI Keywords Are a Myth)

Semantic keywords are words and concepts that are substantively connected to your main keyword and help Google understand the context and the meaning of your page. If you write about lead generation, terms such as funnel, conversion, follow-up and sales cycle logically belong to it. By using those related concepts naturally, your page reads to Google like a complete resource instead of a thin text around a single word. In this article you will read what semantic keywords exactly are, how to use them and why the popular term “LSI keywords” is a persistent myth.

What are semantic keywords exactly?

Semantic keywords are not synonyms of your main keyword in the strict sense. It is about the broader web of concepts that belongs to a topic:

• Synonyms and variants of the same concept.
• Related concepts that logically connect to the theme.
• Sub-questions and sub-themes a reader expects.
• Industry terms that show you really master the subject.

Modern search engines stopped working on exact word matching a long time ago. They understand that a topic consists of several connected concepts and recognise whether a page genuinely covers a theme or merely talks about it on the surface. That is the core of semantic search: Google reads meaning, not just letters. If you want to understand the basics first, read our explanation of what SEO is.

The LSI myth: what is wrong with it?

You often hear semantic keywords called “LSI keywords”. The term sounds technical and reliable, but it is misleading.

LSI stands for Latent Semantic Indexing, an information technique from the 1980s designed for small, clearly bounded document collections. The idea took hold that Google would use that technique and that a list of “LSI keywords” would get you ranking higher. Google spokesperson John Mueller was crystal clear about that in 2019: there is no such thing as LSI keywords. Google has never applied that technique.

What Google does use is far more advanced: natural language processing, machine learning, entities via the Knowledge Graph and vector representations of meaning. The practical consequence matters: you do not need to work a magic list of terms into your text in order to rank. You simply need to handle a topic completely and clearly. So you can happily drop the term LSI, while the idea behind it (using related concepts) remains useful, just for a different reason.

Semantic keywords versus long-tail keywords

These two are often mixed up, but they are different things.

• Long-tail keywords are specific, longer queries somebody actually types in, for example “accounting software for small construction companies”. They are concrete queries with generally lower volume and higher buying intent. You can read more about that in long-tail keywords for B2B.
• Semantic keywords are the related concepts you work into your text to make the topic complete. They are not necessarily queries somebody types in, but building blocks that provide context.

In short: long-tail keywords determine what you aim at, semantic keywords determine how completely you handle that topic. In practice, they reinforce each other.

How do you use semantic keywords well?

It is not about hiding extra words, but about handling a topic naturally and completely. A few principles:

1. Start from search intent. Think about what else your reader wants to know when they land on your page, and cover those questions.
2. Write the way your audience talks. Use the industry terms and phrasings your customers use themselves, not an artificially inflated word soup.
3. Look at the search results themselves. The “people also ask” blocks and related searches in Google reveal which sub-themes belong to your topic.
4. Build topical coherence. Refer via on-page SEO and internal links to related articles, so Google sees that you cover an entire theme.

The pitfall is keyword stuffing: artificially repeating the same words. That reads badly and does not work, because Google assesses topics, not word counts.

Honestly: what does this count for in B2B?

We would rather say it right away: as a small B2B company, you do not win by cramming as many terms as possible into a text. You win by handling a topic close to your expertise so thoroughly and so clearly that both Google and the reader see you as the authority. That is exactly what semantic keywords are for: they are the natural proof that you really master a theme.

Being small and focused is even an advantage here. By building a few connected articles around your core theme, you cover that topic more deeply than a large player who writes half-heartedly about everything. Our SEO approach therefore does not start from a list of keywords, but from the question of which topics genuinely occupy your audience and lead to leads. Steer on customers and revenue, not on a word list that looks good in a tool.

Frequently asked questions about semantic keywords

What are semantic keywords? Semantic keywords are words and concepts that are substantively related to your main keyword. They help Google understand the context and meaning of your page, so it sees that you cover a topic completely.

Are LSI keywords the same as semantic keywords? The term LSI keywords is a myth. Google has confirmed that it does not use Latent Semantic Indexing. The idea behind it, using related concepts, is correct, but the name LSI is technically wrong.

How many semantic keywords should I use? There is no fixed number. If you handle your topic completely and in natural language, the right related concepts appear on their own. Focus on completeness, not on a quota.

What is the difference with long-tail keywords? Long-tail keywords are specific queries you aim at. Semantic keywords are the related concepts you work into your text to handle that topic completely.

Do you want content that really performs?

Semantic keywords are not a trick, but the result of good work: handling a topic completely in the language of your audience. We find out which themes deliver leads for your B2B company and which ones you are better off leaving alone. We are a small team that moves fast and thinks along honestly. Schedule your free intake