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Plagiarism Checker

Scan text for unoriginal content with source matching

Source matching Free, no signup
Humanize Detect Plagiarism
Your Text 0 words

Minimum 50 words recommended for accurate results

Free, no signup required

Plagiarism results appear here

Paste at least 30 words and click Check Plagiarism to scan for copied content.

Process

How It Works

  1. 1

    Paste your text

    Copy and paste the text you want to check. A minimum of 30 words is required, and 50 or more gives the most reliable source matching.

  2. 2

    Run the scan

    The checker searches for matching phrases across the web and scores originality based on direct matches, sentence patterns, and repetition signals.

  3. 3

    Review flagged passages

    See your originality score, matched sources, and sentence-by-sentence flags. If needed, send the risky passages to Humanizer for a cleaner rewrite.

FREE
Free

3/day, 300 words, 5 modes

STARTER
$9.99/mo

30K words, 9 modes, batch

PRO
$19.99/mo

100K words, API access, priority

FAQ

FAQ

How does the plagiarism checker work?
Our checker extracts key phrases from your text and searches the web for matches. When web search is available, it finds exact source URLs. It also analyzes text structure, cliche density, and vocabulary patterns to estimate originality even without web search.
Is the plagiarism checker free?
Free users get 3 checks per day with up to 300 words each. The checks include full originality scoring and per-sentence analysis. Upgrade for higher word limits and more daily checks.
What does the originality score mean?
The originality score ranges from 0-100%. A high score (green) means your text appears original. A low score (red) indicates potential matches with existing content online. Use the per-sentence view to identify which parts need rewriting.
Can I fix flagged text?
Yes! If sentences are flagged, click "Humanize Flagged Text" to send them to our AI Humanizer, which will rewrite them to be unique while preserving meaning.
Is my text stored?
No. Your text is analyzed in real-time and not stored permanently. Logged-in users get a brief history entry for convenience, but the full text is never retained beyond processing.
What word count do I need for accurate results?
A minimum of 30 words is required, but 50 or more words produce the most reliable results. Short snippets lack enough context for meaningful web matching. For academic or professional submissions, we recommend checking the full document rather than individual paragraphs.
Does it detect paraphrased plagiarism, not just exact copies?
The checker identifies both exact phrase matches and near-duplicate sentences. It also flags generic or clichéd language patterns common in AI-generated and template-copied text. For highly paraphrased content, some matches may score lower — always review flagged sentences in context.
Can it check academic papers and student essays?
Yes. Paste the full text of an essay, research paper, or report and the tool will scan it against web sources and assess sentence-level originality. For formal academic submission, this provides a useful preliminary check, but institutional plagiarism platforms (like Turnitin) may access additional databases.
How does this compare to Turnitin or Grammarly plagiarism?
Turnitin accesses proprietary academic databases we cannot. Grammarly plagiarism requires a paid plan. Our tool scans against the open web with per-sentence analysis — free, no account needed. Use it as a fast first pass before submitting to institutional checkers.
Does it work on mobile?
Yes. Paste text on your phone and tap Check. The originality gauge, matched sources, and per-sentence analysis are all fully responsive. You can also upload .txt files from your device.
Can I check content in languages other than English?
The tool works best with English text. Web matching may return results for other Latin-script languages, but the linguistic analysis (cliche detection, vocabulary patterns) is optimized for English.
What should I do after flagged sentences are found?
Click "Humanize Flagged Text" to send them to our <a href="/ai-humanizer">AI Humanizer</a>, which rewrites flagged passages to be unique. You can also run the rewritten text through our <a href="/ai-detector">AI Detector</a> to confirm it reads as human-written.
Can I download the plagiarism report?
Yes. Click "Download Report" to save a full .txt report containing the originality score, matched sources, flag summary, and per-sentence analysis. Useful for documentation or sharing with editors.
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Coda One's Plagiarism Checker scans your text against billions of web sources to detect copied content. Get an overall originality score, matched source URLs with similarity percentages, and per-sentence analysis highlighting flagged passages. If plagiarism is detected, use the built-in Humanize feature to rewrite flagged text into unique, original content. Free to use with no signup required.