Plagiarism Checker
Compare two documents and see exactly which passages overlap
Paste a source document to compare against. Leave empty to scan for repeated passages inside your own text.
Paste your work, add a source document, and the checker breaks both into overlapping five-word runs and finds every sequence that appears in each. Leave the reference box empty and it scans your own text for repeated passages instead — useful for spotting padding before you submit. Matched phrases are listed in full so you know what to rewrite.
How it works
Paste your text
Drop your draft into the box, or upload a .txt file if it is already saved somewhere.
Run the tool
One click starts the analysis. Longer passages give a steadier result than a single sentence.
Read the breakdown
You get a headline result plus the underlying measurements, so you can see how the score was reached.
Why people choose ZeroGPT
Runs in your browser
Nothing you paste or upload is sent to a server. Plagiarism Checker works offline once the page has loaded.
Free, with no account
There is no sign-up wall, no credit card and no daily limit hiding behind a paywall.
Built for real work
Plagiarism Checker is designed for students, writers and editors who need an answer in the middle of a task, not a demo.
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Fifteen free tools for writing, checking and cleaning up your work — all running in your browser.
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AI Translator
Move text between languages without losing the sense
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Word Counter
Every number you need about a piece of writing, live as you type
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Definitions, pronunciation and synonyms in one lookup
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Frequently asked questions
Is Plagiarism Checker free to use?
Yes. Every tool on ZeroGPT is free, with no account, no trial period and no credit card. There is nothing to unlock.
Is my text or file uploaded anywhere?
No. Plagiarism Checker runs entirely in your browser using JavaScript. Your content is read from the page, processed on your device, and discarded when you close the tab.
How accurate is it?
It is a strong signal, not a verdict. Plagiarism Checker measures statistical patterns, and patterns can be wrong in both directions. Use the result as one input into your own judgement, especially when the stakes are high.
Does it work on my phone?
Yes. The layout adapts to small screens and the tools are built to work with touch. Very large files may be slower on an older phone.
Which languages are supported?
ZeroGPT is available in English, French, German, Spanish, Italian and Portuguese. The text tools work best on English but handle other Latin-script languages reasonably well.