Overview
Introduction
Keyword density has a mixed reputation in SEO: it was central to how early search engines ranked pages, it's been publicly dismissed by Google as a ranking factor for over a decade, and yet checking it is still genuinely useful - not to hit a target percentage, but to catch text that repeats a phrase so often it reads as mechanical rather than written for people.
This tool tokenizes pasted body text and reports how often each word and phrase occurs, both as a raw count and as a percentage of total words, so you can spot unintentional over-repetition (or under-emphasis) before publishing.
What Is Keyword Density Checker?
A client-side text analyzer that breaks pasted copy into words, counts single-word frequency (excluding common English stopwords like "the" and "and"), and separately counts 2-word and 3-word phrase frequency without any filtering.
It works entirely on the text you paste - there's no fetching, no HTML parsing, and no external service involved, so it works equally well on a finished article, a draft in a text editor, or a competitor's copy you've copied for comparison.
How Keyword Density Checker Works
Text is lowercased and split into words using a simple alphanumeric-plus-apostrophe pattern, which strips surrounding punctuation while keeping contractions intact. The single-word table then removes a built-in stopword list (articles, prepositions, common pronouns, and so on) before counting frequency, since otherwise "the" and "and" would dominate every result.
Phrases are built by sliding a 2-word and separately a 3-word window across the full, unfiltered word list, so "in the cloud" stays intact as a phrase even though "in" and "the" would individually be filtered out of the single-word table. Every count is then expressed as a density percentage of the total word count.
When To Use Keyword Density Checker
Before publishing a page targeting a specific keyword, to confirm it (and its natural variations) actually appears in the body copy at a reasonable, non-mechanical frequency rather than being missing entirely or crammed in unnaturally.
When reviewing AI-assisted or outsourced content for repetitive phrasing, since generated or templated text sometimes repeats the same 3-word phrase far more than a human writer naturally would.
Often used alongside Meta Tag Checker and Heading Structure Analyzer.
Features
Advantages
- Separates single-word and multi-word phrase frequency, since a target keyword is often a phrase ("project management software"), not a single word.
- Works entirely offline on pasted text - no fetching, no CORS concerns, and no risk of exposing draft or embargoed copy to a third-party service.
- Flags disproportionate repetition without pretending there's an official 'correct' density to aim for.
Limitations
- The stopword list is English-only and fixed; running non-English text through the single-keyword table will filter nothing (or filter the wrong words), though the phrase tables still work language-agnostically.
- This is a mechanical word-count tool, not a semantic one - it can't tell that "running shoes" and "trainers" mean roughly the same thing, so it won't catch a page that's topically thin despite low literal keyword repetition.
Examples
Best Practices & Notes
Best Practices
- Write for the phrase your reader would actually type, then check that it (and close natural variations) shows up in the phrase tables a handful of times across a full-length page - not dozens.
- Treat any single keyword flagged over 3% as a prompt to reread that paragraph aloud; if it sounds repetitive to your ear, it will likely read that way to a search engine's language model too.
Developer Notes
Tokenization intentionally keeps internal apostrophes (so "don't" is one token) but strips all other punctuation; phrase n-grams are built from the raw word list before stopword filtering so multi-word phrases stay grammatically intact.
Keyword Density Checker Use Cases
- Checking a finished blog post for accidental over-repetition of a target keyword before publishing
- Comparing your draft's phrase frequency against a competitor's published article for the same topic
- Auditing AI-generated or templated copy for mechanical-sounding repeated phrases
Common Mistakes
- Chasing a specific 'ideal' density percentage that doesn't correspond to any real Google ranking signal, at the expense of natural-sounding writing.
- Only checking the single-keyword table and missing that a target phrase like "best hiking boots" is being repeated far more often as a unit than any individual word within it suggests.
Tips
- Paste just the body/article text, not the full page HTML - navigation, footer, and sidebar text will otherwise skew the frequency counts.