Free · Open source · For Windows
Two small, fast programs built on the same text-matching engine. They work entirely on your own computer, so your documents are never uploaded, stored, or seen by anyone else.
Your documents never leave your computer.
No installation, no account, no internet connection needed.
Compares documents with each other and shows you every phrase they share. Teachers use it to catch plagiarism and copying between students; researchers use it to trace how text moves between sources.
Looks inside one document, or a whole book, for phrases it repeats. Writers and editors use it to catch the paragraph that was moved but never deleted, and the sentence that turns up twice.
WCopyfind and WRepeatfind read and compare your files right where they are, on your own PC. Nothing is uploaded, nothing is stored in the cloud, and no one else's computer ever sees your text. There's no account to create and nothing to sign in to, and the programs work without an internet connection.
That makes them safe for the documents that matter most: student papers, unpublished manuscripts, theses, legal and business files, and anything confidential. Many online plagiarism checkers keep a copy of every paper submitted to them. These programs keep nothing, because they never receive anything.
The one exception is by your choice: if you add an internet shortcut to WCopyfind, it downloads that web page to compare it. It never sends your documents anywhere. Read the full privacy statement.
| If you want to… | Use |
|---|---|
| Check a class set of papers for copying between students | WCopyfind |
| Check papers against sources, past years' papers, or web pages you've saved | WCopyfind |
| See how much text two versions of a document, two bills, or two news stories share | WCopyfind |
| Find accidental repetition in an article, thesis, or report before you publish it | WRepeatfind |
| Find passages repeated between the chapters of a book manuscript | WRepeatfind |
| Catch your own pet phrases and overused sentences | WRepeatfind |
Everything happens on your own computer. No uploads, no cloud, no account, and no copy of your documents kept anywhere.
A clever sorting approach lets WCopyfind compare hundreds of documents, and WRepeatfind check a whole book, in seconds.
Both programs are free for everyone and open source under the GNU General Public License. The code is on GitHub.
Word documents (.docx and .doc), plain text, web pages, and PDFs that contain text. Any language that puts spaces between words works.
Reports open in your web browser, with matching passages highlighted, so you can see exactly what was copied or repeated.
Each program is a single file. Unzip it and run it; delete it when you're done.
WCopyfind grew out of software that Lou Bloomfield, a physics professor at the University of Virginia, wrote in 2001 to check the term papers in his large introductory physics course. He has shared it freely ever since, and it has been used by teachers and researchers around the world for more than twenty years.
In 2026 it was modernized, and WRepeatfind joined it, answering a request readers had been making for years: a way to find the repetition inside a document.
