What the Keyword Density Checker does
The keyword density checker analyzes a text and lists the words and phrases you use most. For single words, two-word and three-word phrases it shows how often each appears and what share of the text it makes up. Enter a focus keyword to see exactly how often it is used and its density in percent.
This is useful in two directions. It confirms that your main topic is clearly present — a page about “image compression” should actually mention it — and it reveals unnatural repetition that makes a text hard to read and can look like keyword stuffing to search engines. Common filler words such as “the”, “and” or “of” are ignored by default so the meaningful terms stand out.
Word detection uses your browser’s language rules and works with English, German, Spanish, Persian and many other languages. The text is analyzed locally and never uploaded.
When to use it
Before publishing
Check that the focus keyword and related terms appear naturally in a new article or landing page.
Editing and readability
Spot words you repeat too often and replace some of them with synonyms.
Competitor analysis
Paste the text of a well-ranking page to see which terms and phrases it covers.
Product descriptions
Make sure important attributes and product names are mentioned without overdoing it.
Tips for the best results
- Write for people first. Use your main keyword in the title, the first paragraph and a subheading, then let it appear naturally.
- Look at the two- and three-word phrases: they often reveal the real topics of a text better than single words.
- Related terms and synonyms matter more than repeating one keyword; modern search engines understand topics.
- Paste only the main content of a page, without menus and footers, for meaningful results.
How the Keyword Density Checker works
The text is split into words with the Intl.Segmenter API, which applies language-specific word rules, and converted to lowercase. Phrases are formed by sliding a window of one, two or three words across the text.
Phrases that begin or end with a filler word are skipped when the filter is on, and only phrases that appear at least twice are listed. Density is the number of words belonging to that phrase divided by the total number of words: occurrences × phrase length ÷ total words × 100.
The focus keyword is matched as a complete phrase, word by word, so “PDF tools” is not counted inside “PDF toolset”.