Plagiarism & Writing
Duplicate Content Checker
Compare multiple text blocks to find duplicate and similar content. Shows similarity matrix and highlights matching phrases between documents.
100% private — processed in your browser only
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How to use Duplicate Content Checker
1
Add text blocks
Enter 2–5 text blocks using the panels below. Click + Add Block to add more.
2
Click Check Duplicates
The tool computes similarity between every pair of texts.
3
Review the matrix
See the similarity matrix and matching phrases between the most similar pair.
Your privacy is protected
This tool runs entirely in your browser. Files you upload are never sent to any server — they are processed locally using JavaScript and immediately discarded when you close the page.
Frequently Asked Questions
How many text blocks can I compare?
Between 2 and 5 text blocks at once.
What similarity threshold indicates duplicate content?
Generally, 70%+ similarity is a strong signal of duplicate or heavily reused content. 30–70% suggests significant overlap.