Keyword Density — What It Is and How to Check It

Updated October 2026 · 3 min read

Keyword density is the percentage of times a keyword appears relative to the total word count of a page. It was once a major ranking factor; today it is a minor signal, but extreme over-use (keyword stuffing) is actively penalised by Google.

The Formula

What Is the Ideal Keyword Density?

There is no official Google guideline, but most SEO practitioners target 1–2% for primary keywords. Anything above 3–4% risks looking like keyword stuffing to Google's algorithms. More important than density is natural usage — write for humans first, use synonyms and related terms, and ensure the keyword appears in the title, first paragraph and at least one H2.

TF-IDF — The Modern Approach

Modern SEO tools use TF-IDF (Term Frequency–Inverse Document Frequency) rather than raw density. TF-IDF measures how important a term is in your document relative to a large corpus of documents. A keyword that appears often in your page but rarely across the web is a strong relevance signal. Tools like Clearscope and Surfer SEO use TF-IDF to suggest related terms — these are often more valuable than repeating the primary keyword.