Keyword density is the simplest health check you can run on a page: which words and phrases does your text actually repeat, and how often? This keyword density checker counts every 1, 2 and 3-word phrase in your copy and shows each one’s frequency and density percentage, so you can spot over-optimised text, accidental stuffing and topics your draft mentions far less than you think.
Paste your text, choose whether to exclude stop words like “the” and “of”, and the analysis runs instantly — entirely in your browser, nothing is uploaded. A Spanish version of this tool is also available: Analizador de Densidad de Palabras Clave.
What keyword density actually measures
Density is a share, not a score: the number of times a term appears, divided by the total words counted, multiplied by 100. If a 500-word article uses “garden storage” 10 times as a two-word phrase, its phrase density against the full text is 2%. Single words behave the same way — a word used 25 times in 500 words has a density of 5%. This checker reports all three levels side by side because they tell different stories: single words reveal your true topic vocabulary, two-word phrases expose your keyphrases and product names, and three-word phrases catch boilerplate, repeated calls to action and sentences you pasted in twice.
The stop-word toggle matters more than it looks. In raw English text, function words — the, of, and, to, a — typically occupy 40 to 50 percent of all tokens and would drown the top of every table. Excluding them (the default) shows the content words you actually chose. Leave them in when you are analysing style or readability, because function-word patterns are part of an author’s fingerprint, and include them when you compare two drafts of the same page and want identical denominators. Note that the denominator changes with the toggle: percentages are always calculated against the words that remain counted, and the tool states both numbers at the top.
How to read the results without fooling yourself
There is no magic density that ranks a page. Search engines stopped rewarding a target percentage long ago; what density still does well is diagnosis. A single-word density above roughly 4-5% for a non-topic word usually means clumsy repetition you can rewrite. A target keyword that appears less often than unrelated words is a sign the page drifted away from its intended topic. Three-word phrases repeated many times word-for-word are the classic fingerprint of templated or spun text — natural writing varies its phrasing, so identical long phrases should be rare outside names, titles and fixed expressions. Use the tables as a map of what your text emphasises, then edit for a human reader: vary synonyms, merge repeated sentences, and let important phrases recur because the paragraph needs them, not because a quota says so.
A quick worked example
Take the sentence: “The cat sat on the mat. The cat ran, and the cat hid.” That is 13 tokens. Raw counts: “the” appears 4 times (30.77%), “cat” 3 times (23.08%), and the two-word phrase “the cat” 3 times (23.08%). Turn stop-word exclusion on and the denominator drops to 6 content words (cat, sat, mat, cat, ran, cat, hid is 7 — count them: cat ×3, sat, mat, ran, hid = 7): “cat” is now 3 of 7, a density of 42.86%, and the top phrase becomes just “cat”. Same text, two honest views — which is exactly why the tool shows you the counted-words total instead of hiding it. On a real 1,500-word draft the same mechanics surface the phrases you did not realise you were repeating in every section.
When this tool helps most
Run it before publishing a page you optimised by hand, to confirm the title’s keyphrase genuinely runs through the copy. Run it on an old post that gets impressions but no clicks, to check whether the text still matches the query it ranks for. Run it when editing AI-assisted or multi-author drafts, where repeated stock phrases creep in section by section. And run it on competitor copy you admire — not to copy their percentages, but to learn which subtopics and entities their text covers that yours skips. Density is a flashlight, not a finish line: it shows you where the repetition and the gaps are; the rewriting is still yours.
Frequently asked questions
What is a good keyword density? There is no ranking threshold. As a writing check, most natural pages land between 0.5% and 3% for their main keyphrase. Treat anything far outside that as a prompt to re-read the text, not as a rule.
Does the checker count my keyword in headings separately? No — paste text is analysed as one stream. If you want heading density, paste only your headings. The tool counts exactly what you give it, nothing hidden.
Are phrases counted across sentence boundaries? Yes: tokenisation treats the pasted text as a continuous stream, so a phrase spanning a full stop can appear in the 2 and 3-word tables. For very short texts this is visible; for articles it affects only a handful of boundary phrases.
Is my text stored or sent anywhere? No. The analysis is pure JavaScript in your browser; you can even disconnect from the internet after the page loads and it will still work.
Related tools
Versión en español: Analizador de Densidad de Palabras Clave: porcentaje exacto de tus palabras clave. You may also like: Title Tag Pixel Width Checker · Readability Checker.
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