Plagiarism Checker
PopularCompare two documents for potentially matching content.
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About Plagiarism Checker
Sometimes the question is narrower than whether text was copied from somewhere: does this draft overlap with the source I already have open? Paste both documents. The page counts shared three-word phrases itself, asks our server for a meaning-based score, and blends the two into one overall figure, with matching phrases highlighted side by side. Only the two texts you provide are compared, so it cannot find copying from anything you did not paste.
Features
- Compares exactly the two documents you paste, with no web or database lookup
- Word-overlap score built from shared three-word phrases
- Meaning score from the all-MiniLM-L6-v2 sentence-embedding model on our server
- Overall Similarity weights meaning at 65% and word overlap at 35%
- Matching phrases highlighted in both documents
- Falls back to word overlap alone if the semantic score is unavailable
Limitations
- It does not search the web or any library of published work, so it cannot show where text came from.
- A high score is not a verdict: quotations, boilerplate and common topics raise it, so read the highlighted passages yourself.
- Each document can be up to 50,000 characters.
- Both texts go to our server for the meaning score, the result is held for a limited time and then cleared, and a daily run limit shared with the other AI tools applies.
How it works
- Paste the first text into Document A and the second into Document B.
- Select Check for matching content.
- Read Overall Similarity, Potential Matching Content and High-Overlap Sections; the overall figure appears once the semantic score arrives.
- Look through the highlighted phrases in the side-by-side view of both documents.
- Use the reset button to clear both documents and compare another pair.
Example input
Document A: "Climate change is primarily caused by human activities, especially the burning of fossil fuels."
Document B: "Climate change is mainly caused by human activities, particularly the burning of fossil fuels."Frequently asked questions
- No. It compares document A with document B and nothing else. For matches against published sources you would need to paste those sources in, since the tool never crawls pages or searches a database.
- It is 35% of the word-overlap score plus 65% of the semantic score, rounded. Meaning is weighted higher because that score is harder to game by swapping words for synonyms.
- It counts the matching phrases the page highlights, which are shared runs of three words, or single words if either text is very short. The list is capped at 12, so a text with heavy overlap still shows 12.
- The word-overlap score is calculated instantly on the page, but the semantic score is computed on the server, and the first request after a quiet period can take longer while the model loads. The page shows a pending note until it arrives.
- Both use the same two scores. This one gives a single Overall Similarity with in-text highlights; the Text Similarity Checker shows the scores separately and adds the closest matching sentence pair.
Related tools
- Advanced Similarity CheckerCompare two texts by lexical overlap and semantic meaning.
- AI Content OptimizerAnalyze content for readability, structure, and topic coverage.
- AI RewriterRewrite text in a professional, clear, concise, or other style.
- AI ParaphraserRephrase text at light, moderate, or strong intensity.
- Word CounterCount words, characters, sentences and get reading time.