Plagiarism Checker Tool (Client-Side)

The Plagiarism Checker is a fast, private way to compare two pieces of writing without sending anything off your device. It runs entirely in your browser—no uploads, no accounts, no API keys—so you can safely check blog posts, landing pages, proposals, assignments, or internal notes before you publish or share. The tool calculates two complementary scores: Cosine similarity (TF-IDF weighted), which measures how close the two texts are based on the importance of their terms, and Jaccard similarity (unique words), which looks at overlap in vocabulary. You also get highlighted common words so you can see exactly where phrasing converges. The goal isn’t to police style; it’s to give you clear, actionable signals that help you rewrite confidently, add citations, or confirm originality in minutes.

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Plagiarism / Similarity Checker (Pro v2)

Client-side checker with Cosine (TF-IDF), Jaccard (words), and Jaccard (3-word phrases). Toggle stemming to improve paraphrase detection.

Cosine: – Jaccard (words): – Jaccard (phrases): –

Shared word highlights

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Shared word highlights

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Common 3-word phrases

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Note: This is a quick screening tool. For academic/legal use, also run a professional scan.

How to use this Plagiarism checker

  1. Paste Text A — your draft or the passage you want to verify.
  2. Paste Text B — the source, reference, or competing text.
  3. Click Check Similarity to calculate scores.
  4. Review the results:
    • Cosine (TF-IDF): content-weighted closeness on a 0–100% scale (higher = more similar).
    • Jaccard (word): unique-word overlap on a 0–100% scale.
  5. Scan the Highlights area to see shared wording in context. If overlap feels high, rewrite or cite.

What the scores mean

  • Cosine (TF-IDF) emphasizes important terms. If the same distinctive nouns and phrases repeat, this score climbs quickly—even when sentence structures differ.
  • Jaccard (word) is stricter because it counts only unique word overlap. Two long texts that discuss the same topic in different language can show a lower Jaccard even with a moderate Cosine.

Tip: For a solid rewrite, aim for lower Jaccard and moderate/low Cosine by changing structure, verbs, and examples—not just swapping synonyms.

When to use this Plagiarism checker vs. a pro tool

Use this checker for quick screening: drafts, webpages, client deliverables, or knowledge-base entries. For academic submissions, legal documents, or compliance workflows, pair this with a professional plagiarism Cheker that compares against larger proprietary databases and journals.

Best-practice checklist

  • Cite sources for quotes, statistics, and frameworks.
  • Paraphrase deeply: change structure, order, and examples—not only words.
  • Add original value: your analysis, data, screenshots, or case notes.
  • Check the riskiest parts: intros, conclusions, and definition sections.
  • Avoid sensitive or private data in both text boxes.

Privacy & limits

  • Runs client-side; nothing is stored or transmitted.
  • Optimized for English; other Latin-script languages may work, but stop-word handling is tuned for English.
  • Compares two texts at a time; run multiple passes for multiple sources.

Limitations

This plagiarism checker is a quick screening aid. It doesn’t crawl the web or paid databases, and it can’t judge intent. Always cite original sources, apply your professional or academic guidelines, and consider running a database-backed scan for high-stakes submissions.

FAQs- Plagiarism checker

  1. Does this Plagiarism checker tool upload my text anywhere?

    No. Everything happens locally in your browser; nothing leaves your device.

  2. What is a “good” score?

    There’s no universal cutoff. Treat scores as signals and use the highlights to guide edits. High Cosine + high Jaccard usually means close wording; high Cosine + low Jaccard often means similar ideas expressed differently.

  3. Can I compare more than two sources?

    Yes—run several passes, or combine the most relevant paragraphs into Text B to create a composite comparison.

  4. Why do short texts show extreme scores?

    Short passages are sensitive to a few repeated words. Compare at least a few sentences for more stable results.

  5. Will it catch paraphrasing?

    It can indicate paraphrase risk (especially via Cosine), but it doesn’t crawl the web. Always add human review and proper citations.

Check plagiarism in seconds.
Plagiarism Checker — Free & Fast — Paste text, scan for matches, see sources.