Technical SEO
TF-IDF
TF-IDF (Term Frequency-Inverse Document Frequency) is a numerical statistic from information retrieval used to reflect how important a word is to a document in a collection. Term Frequency (TF) measures how often a word appears in a document, while Inverse Document Frequency (IDF) down-weights common words that appear across many documents — giving higher weight to distinctive terms.
TF-IDF analysis is used in SEO content optimization tools like Surfer SEO, Cora, and SEMrush's SEO Content Template to identify semantically important terms that top-ranking pages include. These tools compare TF-IDF distributions of top-ranking pages to help writers create more comprehensive and topically authoritative content.
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Related Terms
Content
Keyword Density
Keyword density is the term used to express how often a targeted keyword is used on a web page.
Content
LSI (Latent Semantic Indexing)
Refers to a technique for examining the relationship between content and keywords used which user searches.
Content
On Page SEO
All actions taken to comply with Google criteria and improve the performance of a website on search engine results pages are called On-Page SEO activities.
Technical SEO
Schema (Structured Data Markup)
Machine-readable code, typically JSON-LD, that labels a page's entities and relationships so search engines and AI systems can interpret content with high confidence.