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With the formula TF * IDF you can review the importance of certain words in a text or a web portal compared to all available documents. This formula is used not only to calculate the keyword density but also, for the OnPage optimization: increase the relevance of a web portal in search engines.


Abbreviations TF come from the English expression Term Frequency, Term frequency in Spanish, and determines the relative frequency of a specific definition, a word or a combination of words, in a document. This value is compared to the relative frequency of all other terms in a text, document, or web portal. The formula is composed of a logarithm and is written as follows:


The logarithm prevents a substantial increase in the use of the specific keyword from affecting the final value of the calculation. While the density of a keyword calculates only the percentage of distribution of a word compared to the total number of words in a text, the frequency of term, TFIt also considers the proportion of all the words used in the text.


The term IDF comes from English Inverse Document Frequency and means Inverse Document Frequency. This second part of the formula completes the evaluation analysis of the terms and acts as the TF corrector. Inverse Document Frequency is very important since it includes the document frequency of specific terms in the calculation: it compares the number of all available documents with the number of documents that contain the term. And to finish, the logarithm is in charge of compressing the results:


Finally: the IDF determines the relevance of a text in terms of a specific keyword.

The formulas above calculate the relevance of a document compared to other documents that contain the same keyword. To get useful results, the formula must be calculated for all relevant words in a text.

The larger the database used to calculate the value TF * IDF, the more accurate the result will be.

Relevance for SEO

When talking about TF * IDF applied to SEO, SEO tools users seek the creation of unique texts to boost the positioning of the web portal in search results. Until now, the term density has been used as the only reference for the optimization of texts, despite everything, the formula TF * IDF offers a much more precise way to get the most out of your content.

Since search engines analyze the semantic link between terms, it is very important to make the most of the content of the web portal semantically. This procedure is called Latent Semantics Indexing.

The tool TF * IDF determine the keywords you should use to create unique content for your web portal. This tool not only optimizes your texts in relation to a keyword, but also provides you with the terms that will help you create a truly unique text.

Disadvantages of the TF * IDF tool

To get the most out of your content with the analysis of the Termination Frequency, you should make sure to include all the items that make up your web portal: category titles and product descriptions are very important.

For online stores with only one product on the web, the formula TF * IDF it is not the most suitable since this type of optimization OnPage requires a lot of text. This is because this formula is very powerful and calculates the value of each term found in the document.

To culminate, the formula TF * IDF it does not contemplate the opportunity for the terms to appear grouped, for lexeme rules to be applied, or for synonyms to be used.


Our innovative feature: TF * IDF Ryte Magazine