Count Unique Words
Count how many unique (distinct) words appear in your text.
How to use this tool
- Enter text in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your unique words and the full breakdown beneath it.
Count how many unique (distinct) words appear in your text.
How it works
This tool counts how many distinct (unique) words appear in your text. It compares all words after normalizing for case, so 'The' and 'the' are treated as the same word and counted once. The result gives you the size of the vocabulary used in the text.
Paste any text and the tool instantly returns the unique word count alongside the total word count, letting you calculate vocabulary richness -- the ratio of unique words to total words. A high ratio suggests varied vocabulary; a low ratio indicates repetition.
This metric is useful for writers checking for overused words, educators assessing student writing complexity, content marketers evaluating keyword variety, and developers building text analysis tools who need a quick sanity check.
Punctuation attached to words (trailing commas, periods) is typically stripped before comparison, so 'word' and 'word.' are treated as the same token. Contractions like 'don't' are usually kept as a single unique word.
Worked example
Check vocabulary variety in a paragraph
- Paste: 'The cat sat on the mat. The cat was happy.'
- Total words: 10
- After normalizing case and stripping punctuation, unique words are: the, cat, sat, on, mat, was, happy -- 7 distinct words.
- Vocabulary ratio: 7/10 = 70%.
7 unique words out of 10 total.
Common mistakes to avoid
- Comparing unique word counts across texts of very different lengths -- longer texts naturally accumulate more unique words, so context matters.
- Expecting inflected forms (run, runs, running) to be merged -- they are counted as separate unique words unless stemming is applied.
- Pasting HTML or markdown and not stripping tags first -- tag words like 'div', 'href', or 'strong' will appear as unique words in the count.
Key terms
- Unique word (type)
- A distinct word form appearing in a text, counted once regardless of how many times it occurs.
- Token
- Each individual word occurrence in the text, including repeated instances.
- Type-token ratio (TTR)
- The ratio of unique words to total words, used as a measure of lexical diversity. A TTR of 1.0 means every word is used exactly once.
Frequently asked questions
- Is the comparison case-sensitive?
- No — 'The' and 'the' are counted as the same word.