Reports how often each term and phrase appears in a block of copy, as a count and a percentage. Density has not been a direct ranking factor for many years, so treat it as a diagnostic rather than a target to hit.
It is useful in both directions. Unusually high density is a reliable signal that the copy reads badly and repeats itself; unusually low density for the term a page is supposed to be about often means the page never quite says what it is about.
Frequently asked questions
What is a good keyword density?
There is no target, and any tool that gives you one is selling advice from 2005. Google has used semantic analysis rather than term counting for well over a decade, and deliberately hitting a percentage is keyword stuffing, which is a documented negative signal. The genuinely useful reading is the opposite direction: if the top terms are not what your page is about, or boilerplate outranks your content, that is worth fixing.
Why are two and three-word phrases more useful than single words?
Because search intent lives in phrases. "json" tells you almost nothing; "json formatter" and "format json online" are the actual queries people type. N-gram counts show whether your copy contains the phrasing your audience uses, which single-word counts cannot reveal.
What are stop words and why remove them?
Common function words — the, and, of, to, is — that carry grammar rather than meaning. In any English text they dominate a raw frequency count, so leaving them in produces a list that is identical for every document and tells you nothing. Removing them is on by default; turn it off if you specifically want the true totals.
Does this send my text anywhere?
No. This tool runs entirely in your browser, like almost everything on TweakPad — the text you paste is never uploaded, stored or logged. The one exception on the site is the SEO Analyzer, which has to fetch a URL from our server because browsers cannot request pages from other domains, and its page says so plainly.