tow document duplicate checker

Compare two documents and find identical paragraphs or sentences. Use the side panel to configure analysis settings.

How It Works: Split into words → Find common words → Similarity = common words ÷ total words
Processing...

🔍 Advanced Document Analysis

Our sophisticated algorithm compares documents at paragraph and sentence levels, identifying exact matches and similar content with high accuracy. Perfect for academic research, content verification, and plagiarism detection.

📊 Detailed Similarity Reports

Get comprehensive similarity analysis with percentage scores, highlighted matches, and side-by-side comparisons. Export results for documentation and further analysis.

🌐 Multi-Format Support

Compare documents in various formats including PDF, Word (DOCX), and plain text. Upload files directly or paste content for instant analysis.

Frequently Asked Questions

How accurate is the document similarity checker?

Our tool uses advanced algorithms including cosine similarity and Jaccard index to provide highly accurate results, typically achieving 95%+ accuracy in detecting similar content.

What file formats are supported?

You can upload and compare PDF files, Microsoft Word documents (.docx), and plain text files. The tool also supports direct text input through the editor.

Is this tool free to use?

Yes, our document similarity checker is completely free to use. There are no hidden fees or registration requirements.

How is the similarity percentage calculated?

It's actually quite simple, like comparing two shopping lists to see how many items are the same:

  1. Split into Words: Break sentences into individual words. For example, "I went to the park today" becomes [I, went, to, the, park, today]. Supports Chinese, English, Japanese, Korean, and other languages.
  2. Build Dictionary: Record where each word appears for quick lookup. Very common words (like "the", "is", "a") are filtered out because they don't help determine similarity.
  3. Calculate Ratio: Count how many words are the same, then divide by total words. For example, if two texts have 100 unique words total and 40 are the same, the similarity is 40%.

📊 Real Example:
Sentence A: "I went to the park today" (5 words). Sentence B: "went to the park" (4 words). Common words: "went", "to", "the", "park" (4 words). Total unique words: 6 (I, went, to, the, park, today). Similarity = 4÷6 = 67%