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Expert Picks

Best Plagiarism Detection Tools 2026

Plagiarism detection has moved beyond a single scan—modern tools integrate plagiarism checking with writing assistance, so you catch both accidental overlap and intentional misuse. Grammarly and QuillBot bake it in seamlessly, while PaperRater and ProWritingAid offer it as part of broader academic or professional writing suites. Your choice depends on whether plagiarism checking is your core need or a secondary feature.

  1. 1
    Best OverallFree tier

    Grammarly

    by Grammarly Inc.

    $12

    /mo

    The most widely used writing assistant — grammar, tone, and AI rewrites.

    Visit Grammarly →Full review
  2. 2
    Runner-UpFree tier

    PaperRater

    by PaperRater LLC

    $7.95

    /mo

    Free academic proofreader with AI-powered grammar check and plagiarism detection.

    Visit PaperRater →Full review
  3. 3
    #3Free tier

    ProWritingAid

    by Orpheus Technology Ltd.

    $10

    /mo

    Deep writing analysis with 20+ reports for serious writers and authors.

    Visit ProWritingAid →Full review
  4. 4
    #4Free tier

    QuillBot

    by Course Hero

    $9.95

    /mo

    AI paraphrasing tool with seven rewrite modes and a plagiarism checker.

    Visit QuillBot →Full review
  5. 5
    #5

    WhiteSmoke

    by WhiteSmoke Ltd.

    $5

    /mo

    Multi-language grammar checker with a built-in translator for 55 languages.

    Visit WhiteSmoke →Full review

Final Thoughts

Grammarly's built-in plagiarism check hits the middle ground for most users. QuillBot's detector is faster and its paraphrasing modes help you rewrite your way out of overlap, making it ideal if you're actively revising flagged content.

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