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  • Brief explanation
  • Detailed explanation
  • The logic behind WDF IDF
  • How WDF IDF works
  • The tools that dominate WDF IDF
  • Conclusion


WDF*IDF: Brief explanation

WDF*IDF is a formula by which search engines determine the optimal distribution of topics, relevant terms, and keywords in content. The method for determining this distribution, however, is much more complex than working with keyword density alone. WDF*IDF optimized content also considers the semantic context of keywords.

Graphic with WDF*IDF headline

What is WDF*IDF? Detailed explanation:

The formula WDF*IDF has been an important topic of onpage SEO since 2012. Rather than just searching by keyword, or multiple keywords, it calculates related terms being used on other high ranking sites and then orders these terms by popularity. The data is more accurate because it compares related terms, semantic context and popularity of terms.

The formula uses two factors to analyze articles, IDF and WDF.

WDF is “within document frequency” and describes frequency of a word within a document. IDF stands for “inverse document frequency” or how popular a term is on other sites. This means that the IDF is the popularity rating.

How WDF*IDF  works

Simply put, the more often a word appears in documents that are popular with search engines, the more relevant the keyword. Applying this principle, the WDF*IDF analysis determines the relevance of complementary keywords into a search.

WDF*IDF tools help determine which terms you should include in your content to improve search rankings. They show you the top sites using your keyword and help you add additional words that will rank highly. Text quality is also important because your site is directly compared against the highest competition. For that reason, text quality is crucial and should be interesting, relevant, and well-written.

These tools dominate WDF*IDF analysis

There are various tools that can optimize content according to the WDF*IDF formula for optimal term weighting.

Among the most important providers of WDF*IDF-enabled SEO tools are Seolyze , Xovi,, Sistrix and Search Metrics .


Search Engine Optimization by WDF*IDF formula is a trend in search engine optimization. More and more SEO providers have plug-ins for WDF*IDF. It is a valuable tool to enhance well-written and relevant content for higher search engine results.


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