What Is Keyword Density and Why Does It Matter for SEO?
Keyword density is the percentage of times a specific keyword appears in a piece of text relative to the total word count. It is calculated by dividing the number of keyword occurrences by the total words and multiplying by 100.
For example, if a 500-word article contains your primary keyword 10 times, the keyword density is 2% (10 ÷ 500 × 100 = 2%).
What Is the Optimal Keyword Density?
The SEO industry generally recommends a keyword density of 1–2% for your primary keyword. This is enough to signal relevance to search engines without triggering over-optimisation penalties. Secondary keywords can appear less frequently — 0.5–1% is often sufficient to establish topical relevance.
What Is Keyword Stuffing?
Keyword stuffing refers to the practice of unnaturally repeating a keyword to manipulate search rankings. Google's algorithms are sophisticated enough to detect when keyword usage feels forced or unnatural, and they actively penalise pages that use this technique. A density above 3–4% for any single keyword is generally considered over-optimisation.
TF-IDF and Modern SEO
Modern SEO has largely moved beyond simple keyword density towards TF-IDF (Term Frequency-Inverse Document Frequency), which measures how relevant a term is to a document relative to a wider corpus. Our keyword density checker gives you the raw frequency data that feeds into understanding your content's topical focus.