Definition
LSI keywords, short for Latent Semantic Indexing keywords, are terms and phrases that are conceptually related to a page’s main keyword. They help search engines understand the context and semantic meaning of content, enabling more accurate indexing and better matching with user search intent. Rather than relying solely on exact keyword matches, LSI keywords provide contextual breadth and depth, signaling to search engines that the content comprehensively covers the topic at hand.
Is It Still Relevant?
While the concept of LSI keywords has historical roots in early search engine indexing technologies, the term itself is somewhat outdated in modern SEO. Google has overtly stated that it does not use Latent Semantic Indexing in its algorithms. However, the functional idea behind LSI keywords—using semantically related terms to support content context—is still highly relevant.
Search engines have evolved to use advanced natural language processing (NLP) techniques like BERT and machine learning algorithms to assess content relevance. What’s critical today is producing content that naturally includes a range of related terms, synonyms, and entities, which aid in topic modeling and semantic search. So while the exact term “LSI keywords” might be a legacy concept, the practice it describes remains a cornerstone of effective SEO.
Real-world Context
In practice, marketers and content creators use tools like Clearscope, Surfer SEO, or SEMrush to identify semantically related keywords and concepts that support a piece of content. For example:
– A blog post targeting the keyword “digital marketing strategy” might naturally include LSI-style terms such as “content marketing,” “SEO,” “social media campaigns,” and “conversion rate.”
– An eCommerce product page for a “running shoe” could include related terms like “athletic footwear,” “track shoes,” “cushioning,” and “breathable fabric” to improve contextual relevance.
Well-optimized content that includes such related terms tends to perform better in organic search because it provides more value, satisfies user intent more effectively, and aligns with how modern algorithms evaluate content.
Background
Latent Semantic Indexing originated in the late 1980s as a mathematical method for improving information retrieval through the relationships between words and concepts across documents. This technique aimed to address the limitations of relying solely on keyword matching by introducing semantic similarity.
As search engines evolved in the early 2000s, SEO professionals adopted the term “LSI keywords” to describe the strategy of including contextually related words in content to boost relevance. However, actual LSI as a computational method is rarely, if ever, applied in modern search engine algorithms. Over time, the SEO industry has continued to use the term—even if inaccurately—to refer to the broader strategy of optimizing content through contextually related language.
What to Focus on Today
Today, marketers should focus on holistic content relevance rather than chasing specific “LSI keywords.” Here’s how to optimize effectively:
– Use topical depth: Create content that thoroughly answers questions your audience may have, covering subtopics and related angles.
– Implement semantic SEO strategy: Improve your content’s relationships using entities, synonyms, and semantically linked phrases. Tools like MarketMuse, Frase, and Surfer SEO can help guide content creation.
– Optimize for user intent: Understand what users are really looking for when they search a keyword, and build content that meets that need using natural, context-rich language.
– Avoid keyword stuffing: Instead, aim for natural inclusion of related terms and variations to help search engines understand the topical scope.
– Monitor performance: Use SEO analytics tools such as Google Search Console, Ahrefs, or Semrush to track organic keywords and improve based on real user behavior and trends.
Ultimately, successful SEO content in today’s landscape is about high-quality, contextually-rich content that addresses user needs comprehensively—not jamming in a list of “LSI keywords.”
By evolving from the outdated term to modern semantic optimization practices, marketers can continue to create content that resonates with both users and search engines.