A keyword density checker is a text analysis tool that counts how often each word appears in a passage and divides that count by the total number of words to produce a percentage, helping beginners see whether their draft repeats a target phrase more or less often than they intended. The percentage is descriptive evidence about a single document, not a recipe for ranking, and it stays the same regardless of which device or browser tab you use to view the report. For someone using a keyword density checker for the first time, the value sits in noticing accidental repetition, missing terminology, and editorial imbalance before publishing. The tool works entirely on the text you paste, which means beginners can experiment with their own drafts in a familiar environment without learning a query language, building a spreadsheet, or sending content anywhere. Understanding exactly what the numbers represent, and what they do not, is the first step toward using them well.

What Keyword Density Actually Means for Beginners
Keyword density is the share of the total word count made up by a specific word or contiguous phrase. If a 500-word article mentions the phrase "running shoes" ten times, the phrase density for that term is ten divided by 500 multiplied by 100, which equals two percent. That single formula sits behind every density number you will see in any checker, including the one built into Lizely.
Two details matter right away. First, the denominator is the total number of recognized word tokens in your text, not the number of unique words and not the number of slots where a phrase could start. Second, every percentage is reported against that same denominator, which keeps the math transparent. A beginner who reads a density number and asks, "Out of what?" should now have an answer: out of every word the tokenizer recognized in the pasted text.
Because the percentage comes from a closed document, it tells you about your draft and nothing about your competitors, search volume, or current ranking. Treating the number as a personal editorial signal rather than a target keeps the work grounded in writing quality.
Why a Transparent Local Tool Fits a First Draft
Beginners often worry that pasting a draft into an online tool will send their unpublished writing to a server. The Keyword Density Checker runs entirely inside your current browser tab. Nothing leaves the device unless you copy it elsewhere yourself, which is helpful for early-stage drafts that may still be sensitive, private, or unreviewed. Even so, you should still avoid using shared or public computers for anything you would not want a stranger to read.
The local-only design also matters for trust. Every number you see comes from a clearly stated method: Unicode-aware tokenization, case-insensitive matching through lowercase conversion, a denominator that counts every recognized token, and a frequency table that sorts by count and then alphabetically. There is no hidden weighting, no language detection that might quietly change the rules, and no AI model rewriting your prose. The report simply describes what you pasted.
For a beginner, that level of transparency removes the most common anxiety: acting on a number whose calculation cannot be inspected. You can re-paste the same text, get the same numbers, and verify the result yourself with the formula shown above.
How to Run Your First Density Check in Three Steps
- Paste the visible text you want to inspect into the input box, and optionally type one exact keyword or phrase in the keyword field if there is a specific term whose repetition you want to inspect.
- Choose the minimum word length for displayed single-word rows, then select Check keyword density. The minimum-length control only affects which rows appear in the table; total and unique counts still cover every token.
- Review the counts and the surrounding prose, treating percentages as descriptive evidence about your draft rather than a ranking target you must hit.
Before you start, strip navigation, footer, and repeated template phrases from what you paste. Those elements would inflate totals and distort percentages, especially for shorter articles. Pasting only the main body keeps the report aligned with what readers actually see.
Reading the Frequency Table Without Misreading It
The frequency table shows up to 50 of the most frequent eligible words, sorted by count and then alphabetically for ties. Total word count and unique word count always cover the full input, even when the displayed list is filtered. This split exists for a reason: a beginner can hide one-character rows by setting minimum length to two, then still see the full denominator in the totals, which prevents a filtered table from quietly inflating the apparent density of the rows that remain visible.
Tokenization rules matter here as well. The tool splits tokens on punctuation, dashes, symbols, and whitespace, so a hyphenated form like "red-blue" counts as two separate tokens named "red" and "blue". Internal apostrophes, including the typographic curly form, stay inside the token, so contractions such as "don't" and accented forms such as "l'été" remain single units. Unicode letter and number properties drive the splitting, which means non-ASCII text stays countable. Matching is case-insensitive, so "Red", "red", and "RED" all add to the same row.
| Tokenization rule | Example input | How it is counted |
|---|---|---|
| Whitespace separates tokens | running shoes | Two tokens: "running" and "shoes" |
| Punctuation separates tokens | red, blue. | Two tokens: "red" and "blue" |
| Hyphens and dashes separate tokens | red-blue | Two tokens: "red" and "blue" |
| Internal apostrophe stays inside | don't | One token: "don't" |
| Typographic apostrophe stays inside | l'été | One token: "l'été" |
| Case-insensitive matching | Red, red, RED | Counts merge into one row |
The minimum-length filter is the easiest place to misread a report. Setting it to three hides "to", "of", and "in" from the displayed list, which can make the remaining percentages look higher than they actually are relative to the full text. Always read the displayed percentages against the full denominator printed at the top of the report, never against the count of visible rows.
A worked example can make the rules concrete. Take the short sentence "Red blue red. RED green blue red-blue." The tokenizer finds eight total words. Red appears four times for 50%, blue appears three times for 37.5%, and green appears once for 12.5%. The exact phrase "red blue" occurs twice as a contiguous pair, producing a phrase density of 25% under the documented denominator. Every percentage uses count divided by total tokens multiplied by 100, and phrase matches may overlap with other phrase matches in the text.
What the Tool Deliberately Does Not Do
The Keyword Density Checker has no stop-word list, no stemming, no lemmatization, no synonym expansion, no language detector, no HTML boilerplate remover, and no search-volume data. Each of those features would require language- and corpus-specific reference choices that could change the result depending on which list or stemmer the tool happened to embed. Leaving them out keeps the calculation reproducible.
The tool also does not fetch a URL, render JavaScript, compare competitors, connect to Search Console, estimate ranking difficulty, or publish content. It does not send the pasted text to an AI model. If a feature appears to be missing, the omission is usually deliberate, because adding it would shift the numbers in ways that beginners could not verify from the report alone.
| What the checker does | What the checker deliberately does not do |
|---|---|
| Counts total and unique word tokens with disclosed rules | Remove stop words or apply a language-specific list |
| Reports the 50 most frequent eligible single words | Fetch, render, or analyze a live URL |
| Counts an optional contiguous phrase, including overlapping matches | Connect to Search Console or pull search-volume data |
| Runs entirely in the current browser tab | Send pasted text to a server or an AI model |
| Rejects empty or token-free input instead of returning zeros | Recommend a target density or claim a ranking benefit |
Common Beginner Traps and What to Do Instead
The most common beginner trap is treating a density number as a goal. Google has long warned against keyword stuffing, defining it as the practice of loading a page with keywords in an attempt to manipulate rankings, and recommending that copy focus on useful, readable content instead (Google Search Central, spam policies for keyword stuffing). The Keyword Density Checker reflects that stance directly: it makes no claim that a particular density will improve rankings, and the interface reminds you to treat percentages as descriptive evidence.
A second trap is editing toward a number rather than toward a reader. If the percentage looks low, the temptation is to keep inserting the phrase until the chart looks comfortable, even when the surrounding sentences become awkward. If the percentage looks high, the temptation is to delete every useful occurrence, even when the deletion makes the argument weaker. Both moves make the draft worse. The report is a signal to inspect the surrounding sentences, not a score to optimize.
A third trap is pasting the entire HTML of a page, including navigation, sidebars, footers, and repeated boilerplate. Those tokens still count toward the denominator and they have nothing to do with the article body, so they distort every percentage. Paste only the visible text you intend to inspect, then re-check after edits using the same tokenizer and the same denominator. Comparing revisions fairly requires comparing them under the same rules.
A final note on size and limits. The analysis accepts up to 500,000 characters of input and refuses empty or token-free content rather than returning a misleading zero report. For a beginner, the practical ceiling is rarely a concern; a 5,000-word article sits well below the limit. The refusal of empty input matters more, because it stops a near-empty paste from producing a table that looks meaningful when it actually contains nothing.
Used with that mindset, the Keyword Density Checker becomes a beginner-friendly lens on your own writing. You paste, you count, you read, and you revise for the reader. The numbers support the work; the reader decides whether the work succeeds.