Keyword Density Checker

Density is a simple ratio, occurrences divided by total words, and that simplicity hides several choices that change the result. Two tools can analyze the same page and report different percentages without either being broken.

The denominator is a judgment call

Whether common words such as the, of and and are counted in the total changes every percentage on the page. Including them lowers all densities and reflects the document as written. Excluding them raises the figures and better reflects the meaningful vocabulary. Neither is standard, so comparing a number from one tool against a target quoted from another is comparing two different measurements.

Word forms matter just as much. If a tool treats run, runs and running as three separate terms, a page thoroughly covering a topic will look sparse on each individual form. If it groups them, the same page looks far more focused. Neither approach is wrong, but knowing which one produced a number is necessary to interpret it.

Phrases tell you more than single words

Single-word frequency is the least informative view. A page about running shoes will naturally show high counts for shoes and for running independently, which says almost nothing. Looking at two and three word sequences shows whether the page actually addresses the phrase people search for or merely happens to contain its component words scattered across unrelated sentences.

Length skews everything

Density is a ratio, so lengthening a page lowers it without removing a single mention, and trimming raises it without adding one. Five mentions in five hundred words and twenty mentions in two thousand words report the same density but read very differently. Always look at the raw count alongside the percentage, since the count is the figure that reflects what a reader experiences.

The most useful application of a density report is comparative rather than absolute. Running the same analysis over pages that already rank well for a topic shows the range that occurs naturally in good writing on that subject, which is far more informative than any universal target. What you're looking for is whether your page sits wildly outside that range, in either direction.