Keyword Density
The percentage of times a target keyword appears relative to the total word count on a page.
Definition
Keyword density is the ratio of how many times a target keyword appears on a page compared to the total number of words, expressed as a percentage. The standard formula is: (keyword occurrences ÷ total words) × 100. A page with 1,000 words that uses a target keyword 10 times has a keyword density of 1%.
In the early days of SEO, high keyword density was treated as a strong ranking signal, leading to the practice of "keyword stuffing" — unnaturally repeating a phrase to game search engines. Modern search algorithms, particularly Google's Penguin and Hummingbird updates, penalize this behavior and instead prioritize topical relevance and natural language.
Current best practice is to keep keyword density between 1% and 3% for any single term. More importantly, Google's systems evaluate semantic context, so related terms (LSI keywords) and natural phrasing carry more weight than raw repetition. Use a keyword density tool to audit your content and ensure your primary keyword appears naturally without crossing into over-optimization territory.