If you have spent any time reading about SEO, you have almost certainly come across the term LSI keywords. Tool vendors sell them. Blog posts recommend sprinkling them into your content. Agencies include them in content briefs. And most of it is based on a fundamental misunderstanding of what the term actually means and whether Google uses the underlying technology at all.
The short answer is no. Google does not use LSI keywords in their ranking algorithms. Meaning they are not a ranking factor. In fact, John Mueller, a Google representative, stated in 2019: “There’s no such thing as LSI keywords, anyone who’s telling you otherwise is mistaken, sorry.”
But the longer answer is more nuanced and more useful. The idea behind LSI still matters. Even if the algorithm itself is not used today, the core lesson is evergreen: meaning comes from context. That principle is baked into semantic SEO and modern NLP models like BERT and entity-based ranking systems.
If you are new to SEO keywords generally and want to understand what keywords are before exploring this more advanced topic, our article on what keywords are and why they matter gives a plain-English foundation.
This article explains exactly what LSI keywords are, why Google does not use them, and what you should actually be doing instead to write content that ranks in 2026.
What You Will Learn
- What LSI keywords are and where the term comes from
- Why Google does not use LSI as a ranking factor
- What Google actually uses instead
- What this means for how you write content
- The practical approach to semantic SEO that actually works in 2026
What Are LSI Keywords?
LSI stands for Latent Semantic Indexing. The technology was introduced in a 1988 paper and is described as an approach for dealing with the vocabulary problem in human-computer interaction. In other words, using related words and phrases to better categorise a page’s topic rather than just basing it on individual keywords.
The basic idea was this: if a document about cars also contains words like “engine,” “tyres,” “fuel,” and “mechanic,” a system using LSI could infer that the document is about cars even without relying solely on the word “car” appearing repeatedly. A lot of SEO practitioners grabbed this term and built a myth around LSI keywords, claiming they were a magic list of related words you have to sprinkle into your content to rank.
Latent Semantic Indexing was a mathematical system created in 1988 to find patterns in large sets of text. It was designed to improve document retrieval in early databases, not for search engines.
The term caught on in SEO circles because it sounded technical, provided an easy-to-follow tactic (find the list, add the words), and gave content teams something concrete to include in briefs. The problem is that the tactic is built on a false premise.
Google’s own search results for “LSI keywords” now include multiple results clarifying that the concept is outdated. Understanding what replaced it is the more useful question.
Why Google Does Not Use LSI
LSI was developed before the World Wide Web and was not intended to be applied to such a large and dynamic dataset. As of 2025, there is a clearer consensus: while LSI is a real technique in natural language processing, Google has clearly stated it is not something they have ever used for search rankings.
Google does not use latent semantic indexing because it is older technology that was designed for smaller document sets, not the entire web.
Multiple Google representatives have confirmed this publicly. John Mueller’s 2019 statement is the most direct. Gary Illyes has made similar statements. The technology simply was not built to scale to billions of web pages and dynamically changing content.
The worst advice still circulating around latent semantic indexing SEO is also the most familiar: find a list of LSI keywords, sprinkle them into the copy, and expect rankings to follow. That advice belongs to another era. It confuses an old information retrieval concept with the way modern search systems interpret language.
The phrase stuck around because it sounded smart and technical, offering what felt like an easy win. But chasing a phantom list of LSI keywords forces you to think about content like a robot, not a human.
What Google Actually Uses Instead
Understanding what replaced LSI in Google’s thinking is more useful than debating the term. Google’s modern approach to understanding content involves several technologies that are far more sophisticated than LSI.
BERT and neural language models. BERT (Bidirectional Encoder Representations from Transformers) was introduced by Google in 2019 and represented a fundamental shift in how Google interprets language. Where LSI looked at co-occurrence patterns across documents, BERT reads text the way a human does, understanding the context of each word relative to the words around it in both directions. Our article on Google and AI content covers how Google’s current approach to evaluating content has evolved alongside the rise of AI-generated writing.
Entity recognition. Google uses its Knowledge Graph, a semantic network that stores information about entities such as people and places and their relationships. Google also uses natural language processing to identify entities in content and queries. An entity is a specific, recognised real-world thing: a person, a place, a company, a product. Content that clearly discusses relevant entities signals to Google that it covers a topic with genuine depth.
Search intent evaluation. Google’s algorithms do not just ask “what words are on this page?” They ask “does this page genuinely answer what the searcher was looking for?” A page can contain every related term imaginable and still rank poorly if it does not match the intent behind the search query.
Topical authority signals. Rather than evaluating individual pages in isolation, Google increasingly evaluates whether a website as a whole demonstrates genuine expertise in a subject area. A site with ten well-written, deeply researched articles on SEO strategy will typically outrank a site with one article on the same topic, even if the single article is technically strong.
For a full breakdown of the ranking signals Google actually uses in 2026, our article on top SEO ranking factors covers each one with practical guidance on what to prioritise.
Google’s Knowledge Graph stores information about entities and their relationships. Writing about relevant entities naturally, rather than inserting keyword lists, aligns with how Google actually evaluates content.
What This Means for How You Write Content
The practical question is not “should I use LSI keywords?” It is “how should I write content that Google understands as genuinely comprehensive and relevant?” The answer is different from the LSI approach, and more intuitive.
When experienced SEO professionals talk about LSI today, they are almost certainly using it as shorthand for semantic SEO. They are referring to a much more intuitive and powerful idea: focusing on semantically related terms, synonyms, and the core concepts that holistically define a topic. It is about thinking like an expert, not a robot.
Here is what that looks like in practice:
Write for a human reader who knows the topic
Think about what a genuine expert would write when explaining your topic. They would naturally use the vocabulary that belongs to the subject. An article about Google Ads written by someone who actually understands paid search will naturally include terms like campaign structure, ad groups, Quality Score, cost per click, conversion tracking, negative keywords, and ad scheduling. Not because they are looking at an LSI keyword list, but because these are the concepts that anyone who knows the topic would discuss.
Semantically complete pages are more likely to win SERP features. Featured snippets, People Also Ask placements, and AI summaries pull from content that clearly covers the full topic. This is why semantic depth is now a ranking advantage.
Cover the topic comprehensively
Your real job is to cover a topic so well that there is no question you are an authority. This means discussing related sub-topics, breaking down your main subject into its logical parts.
Before you write, check what the top-ranking pages for your target keyword actually cover. What sub-topics do they address? What questions do they answer? What examples do they use? If the highest-ranking pages consistently cover a particular angle that you have missed, that is a gap worth filling.
Use Google’s own tools to find related concepts
The best free tool for understanding what concepts Google associates with your topic is Google itself. Search for your target keyword and look at the People Also Ask section, the related searches at the bottom of the page, and the subheadings visible in featured snippets. These are Google’s own signals about what concepts are topically related to your keyword.
Our article on how to choose the right keywords for your business covers how to use these signals as part of a broader keyword research process.
Focus on intent, not keyword lists
In 2026, focusing on user intent, thematic relevance, and reading experience is more important than pursuing LSI keywords as a ranking factor.
For every piece of content you write, the first question is: what is the person who searches this keyword actually trying to accomplish? A page that genuinely answers that question, in the most helpful and comprehensive way possible, will consistently outperform a page that technically contains the right keyword list but does not satisfy the underlying need.
The People Also Ask section shows you the questions Google considers related to your topic. Covering these within your content signals comprehensive topical coverage far more effectively than inserting keyword lists.
The Practical Difference Between LSI Thinking and Semantic SEO Thinking
It helps to see the difference between the old LSI approach and the modern semantic SEO approach side by side.
LSI approach: Target keyword is “plumber Brisbane.” LSI keyword tool generates a list: “pipes,” “hot water system,” “blocked drain,” “emergency plumber,” “licensed plumber.” Writer inserts these terms into the content to hit the list.
Semantic SEO approach: Target keyword is “plumber Brisbane.” Writer asks: who is searching this, what do they need, and what would a genuinely helpful, expert answer look like? They write a page that addresses common plumbing issues in Brisbane, explains the licensing requirements for Australian plumbers, answers the questions people actually ask when searching for a plumber, and covers their service areas. The terms “pipes,” “blocked drain,” and “hot water system” appear naturally because they are part of the topic, not because they were on a list.
The output can look similar on the surface but the underlying process produces significantly different quality, and Google’s modern algorithms are increasingly good at telling the difference.
Pages optimised purely around LSI keywords saw 28% lower visibility in AI-generated answers in Q1 2026 compared to content built around entity-focused semantic SEO.
How Semantic SEO Connects to Topical Authority
The modern equivalent of the principle behind LSI is topical authority: the idea that Google rewards websites that demonstrate comprehensive, expert-level coverage of a subject area rather than just optimising individual pages.
If your content reflects a topic’s natural vocabulary and subtopics, you align with how semantic algorithms interpret meaning. The takeaway is the same one LSI started: words matter because of meaning, not repetition.
Building topical authority means publishing a body of content that covers your core topics from multiple angles, linking related articles together intelligently, and consistently demonstrating expertise through depth, accuracy, and original insight.
Our article on topical authority in SEO covers how to build this systematically, including how to structure your content clusters so that each article strengthens the authority of the others. And our article on what EEAT means for SEO covers how Google evaluates the Experience, Expertise, Authoritativeness, and Trustworthiness signals that increasingly determine which pages rank at the top.
The replacement for LSI keyword thinking is intent-focused content. This short explains why matching your content to what the searcher actually wants is the foundation of everything that ranks in 2026.
What to Do Instead of Chasing LSI Keywords
To summarise the practical takeaway from everything above:
Stop: Using LSI keyword tools and inserting related terms to hit a list. This approach is based on technology Google does not use and produces content that optimises for the wrong signals.
Start: Writing about your topic as a genuine expert would, covering the sub-topics and questions that naturally belong to the subject, using the vocabulary that real people in your industry use, and satisfying the intent behind the search query as completely and clearly as possible.
Use Google’s signals: The People Also Ask section, related searches, and the content structure of top-ranking pages all tell you what concepts Google considers topically related to your keyword. These are better guides than any LSI tool.
Build topical depth: A single page cannot establish you as an authority. A body of content that systematically covers your core topics from multiple angles, linked together intelligently, signals genuine expertise to Google in a way that no single article can.
Our article on SEO copywriting covers how to write content that satisfies both Google’s semantic understanding and the human reader’s need for clear, useful information. And our article on how to do an SEO content audit shows how to assess your existing content for topical gaps and semantic depth.
Ready to Write Content That Actually Reflects How Google Works?
The good news about the death of LSI keyword thinking is that the replacement approach is actually easier and produces better content. Write like an expert. Cover your topic thoroughly. Satisfy the intent behind the search. Build a body of content that demonstrates genuine authority in your subject area.
If you want expert guidance on how to apply these principles to your specific website and content strategy, our Free Website and Marketing Review covers your content quality and topical authority as part of a complete SEO assessment. Request yours at ape-x.com.au/review. You can also learn more about how we approach content strategy for Australian businesses on our SEO service page.
