Keyword density

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Keyword density is the percentage of times a keyword or phrase appears on a web page compared to the total number of words. It helps show how relevant a page is to a chosen keyword in SEO. In the early days of search engines, density mattered a lot for ranking. As webmasters learned to optimize it, search engines started weighing other factors more. Today, stuffing keywords often hurts SEO rather than helps.

Search engines now favor semantic SEO: they understand synonyms, context, and overall topics, not just exact word repeats. Density is often discussed with placement factors like proximity (how close terms are to each other) and prominence (how early they appear on the page). These factors influence how search systems judge relevance.

How to calculate:
- For a single keyword: Density = (times the keyword appears / total words on the page) × 100.
- For a multi-word phrase: Density = (times the phrase appears × number of words in the phrase / total words) × 100.
Example: On a 400-word page about SEO, the phrase “search engine optimization” (3 words) appears 4 times. Density = (4 × 3 / 400) × 100 = 3%.

Notes:
- Ignore HTML tags and other non-visible text when counting.
- Treat multi-word phrases as a single unit for counting appearances.

While density can guide optimization, the best practice today is to write clearly for readers and cover topics naturally, focusing on user intent rather than chasing an exact density.