What does IDF stand for?

IDF stands for 'Inverse Document Frequency' and measures how rare a term is across a collection of documents.

Why is IDF important for SEO?

IDF helps determine a term’s relevance to a specific topic, especially in combination with WDF.

What is the difference between WDF and IDF?

WDF measures how often a term appears within a single document, while IDF measures how rare it is across multiple documents.

IDF - IDF – Inverse Document Frequency

IDF stands for "Inverse Document Frequency" and is a metric from search engine optimization and information retrieval. It measures how rarely a term appears across a collection of documents. The rarer a term, the higher its IDF – indicating greater relevance to a specific document. IDF balances WDF (Within Document Frequency) and together they form the basis of WDF*IDF analysis. This method helps optimize content by considering both the frequency and uniqueness of a term.

Measures the rarity of a term across multiple documents
Part of the WDF*IDF analysis
The rarer the term, the higher the IDF
Helps evaluate topical relevance
Used in SEO tools and semantic text analysis