Duplicate Content Checker
Compare two texts for duplicated passages. This free duplicate content checker scores word-sequence overlap with the Jaccard index — Compare now.
Content Similarity Checker
Enter what you want checked below, hit Check, and get a clear pass / warning / fail verdict for every item.
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What is Duplicate content checker?
Content Similarity Checker — Compare two texts for duplicated passages. This free duplicate content checker scores word-sequence overlap with the Jaccard index — Compare now.
Both texts are lowercased and split into word sequences of the chosen shingle size (default 3). The Jaccard index — shared sequences divided by all unique sequences — gives a 0–1 score. Verdict bands: ≥0.90 near-duplicate, ≥0.50 high, ≥0.20 moderate, >0 low, 0 none. This measures overlap between your two texts only; it is not a plagiarism check against the web.
Why use this duplicate content checker?
Built for duplicate content checker
Compare two texts for duplicated passages. This free duplicate content checker scores word-sequence overlap with the Jaccard index — Compare now.
Transparent & honest
Compares only the two texts you paste — it cannot check the web or any search index, so it is not a plagiarism verdict.
Private by design
Everything runs in your browser. Your inputs never leave your device.
Works everywhere
Fully responsive — perfect on desktop, tablet, and mobile. No app needed.
Regularly updated
Regularly maintained and reviewed to ensure accuracy.
Free forever
No accounts, no limits, no watermarks. Use Content Similarity Checker as much as you need.
How to use Content Similarity Checker
- 1Paste the first text into "Text A" and the second into "Text B".
- 2Optionally set "Shingle size" (2–5, default 3) — smaller sizes catch shorter shared phrases.
- 3Run the tool to get the Jaccard similarity score, the percentage, and a plain-English verdict.
- 4Use the verdict bands to decide whether overlapping passages need rewriting before publishing.
What can you do with Content Similarity Checker?
- Internal duplicate content checker — Compare two texts for duplicated passages.
- Text similarity checker — Compare two texts for duplicated passages.
Good to know
- Compares only the two texts you paste — it cannot check the web or any search index, so it is not a plagiarism verdict.
- Shared boilerplate (quotes, disclosures, repeated headers) raises the score without meaning either text copied the other.
How it works
Both texts are lowercased and split into word sequences of the chosen shingle size (default 3). The Jaccard index — shared sequences divided by all unique sequences — gives a 0–1 score. Verdict bands: ≥0.90 near-duplicate, ≥0.50 high, ≥0.20 moderate, >0 low, 0 none. This measures overlap between your two texts only; it is not a plagiarism check against the web.
Examples
Near-duplicate drafts score high.
No shared word sequences scores zero.
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Frequently asked questions
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