Keyword Density Analyzer
A keyword density analyzer is a tool that calculates the frequency of a specific keyword or phrase within a piece of content, expressed as a percentage of total words. It helps writers assess keyword repetition.
- Also called
- Keyword frequency checker
- Applies to
- On-page SEO, content optimisation
- Commonly confused with
- Keyword frequency
Key points
- Keyword density is a historical SEO metric, but Google does not use it as a ranking factor.
- A keyword density analyzer helps identify over-optimisation or under-use of a target phrase.
- Modern SEO focuses on topical relevance rather than exact keyword repetition.
- Density analysis is most useful when combined with semantic analysis tools.
- Avoid rigid density targets; focus on natural language and user intent.
How it works
A keyword density analyzer scans the visible text of a page, counts the total number of words, and then counts how many times the target keyword appears. It calculates the percentage: (keyword occurrences / total words) * 100. Some tools, such as the yoast seo keyword density feature, allow setting a target percentage and flagging if the density is too low or too high. Others may also detect variations like plurals or synonyms.
The output is a single number, often accompanied by a recommendation (e.g., 'increase keyword usage' or 'reduce keyword usage'). The tool typically ignores HTML tags, stop words, and sometimes non-text elements to focus on visible content.
Why it matters
The primary reason to use a keyword density analyzer is to avoid keyword stuffing, a practice that can trigger penalties. Historically, SEOs believed a 1-3% density was optimal, but Google has stated it does not use density as a ranking signal. However, the tool remains useful for quick content audits, especially when combined with semantic analysis.
For example, if you are tracking positions with a keyword rank checker, you might also check density to ensure the page is not under-optimised. A keyword checker can provide a broader view of term frequency across multiple pages. Overall, density analysis is a minor part of modern SEO, relevant mainly for identifying extreme over- or under-use.
Written and maintained by Nora Lindholm. Last updated 27 July 2026.
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