Text Similarity Checker

Calculate real text similarity scores free online using Jaccard and cosine similarity algorithms. Compare two texts and see exactly how much word overlap exists.

How to Use This Tool

Paste your first textOn the left

Paste your second textOn the right

Click CompareSee both similarity scores

Two Real Algorithms, Two Different Perspectives

Jaccard similarity cares purely about which unique words appear in both texts, ignoring how often each word repeats. Cosine similarity builds a word-frequency vector for each text and measures the angle between them, meaning repeated words carry more weight -- genuinely different mathematical approaches that can disagree on the same text pair.

Both Are "Bag of Words" Methods

Neither algorithm considers word order or sentence structure -- "the dog chased the cat" and "the cat chased the dog" would score identically despite having opposite meaning, a known and important limitation of this entire category of similarity measure.

Frequently Asked Questions

The size of the intersection of unique words divided by the size of the union of unique words between two texts -- a measure of word overlap that ranges from 0 (no shared words) to 1 (identical word sets), regardless of word frequency or order.

Cosine similarity represents each text as a word-frequency vector and measures the angle between those vectors, which accounts for how often words repeat, not just whether they appear at all -- a genuinely different mathematical approach that can produce a different score than Jaccard for the same text pair.

Each algorithm captures a different aspect of similarity -- Jaccard cares only about shared vocabulary, cosine also weighs word frequency -- so seeing both gives a more complete picture than relying on a single metric that might miss what the other captures.

No, both algorithms treat text as an unordered collection of words (a 'bag of words' approach), so two texts with identical words in completely different order would still score as highly similar -- a known limitation of this category of similarity measure.

Checking how much two drafts of writing overlap, comparing paraphrased versions of the same content, or getting a rough plagiarism-adjacent signal (though not a substitute for proper plagiarism detection tools) are common uses.

Text Similarity Checker

How to Use This Tool

Two Real Algorithms, Two Different Perspectives

Both Are "Bag of Words" Methods

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Frequently Asked Questions