Frequently asked questions

No, never. WCopyfind reads and compares your documents entirely on your own computer. Nothing is uploaded, nothing is stored in the cloud, and no other computer ever sees your text. It doesn't need an account or an internet connection. That makes it safe for student papers, unpublished work, and confidential documents. Unlike many online plagiarism checkers, it keeps no copies of anything: it never receives anything to keep.

The only time WCopyfind uses the internet is when you give it an internet shortcut to a web page, and then it only downloads that page. See the privacy statement.

Yes, for anyone and any purpose: schools, businesses, research, or personal use. There's no trial period, no paid version, and no advertising. It's open-source software under the GNU General Public License, version 3 or later.

Yes. You can use it however you like, and install it on as many computers as you want. You may also modify it and share your changes; if you distribute a modified version, the GNU General Public License requires you to share its source code under the same license. The source code is on GitHub.

No. WCopyfind compares only the documents you give it. Searching the whole web requires a large commercial service. WCopyfind can, however, compare web pages you point it to: save them as .html files, or create internet shortcuts to them (drag the address from your browser to a folder) and add those shortcuts to the old documents list. If a phrase in a paper sounds unoriginal, searching for it in a search engine often finds the source, which you can then add.

Far more than two. A class set of a few hundred papers takes seconds, and researchers use it on much larger collections. The limits are your computer's memory and your patience, since the number of pairs grows with the square of the number of documents: 100 documents make 4,950 pairs, and 1,000 make 499,500.

Yes. Put both in the new documents list (or one in each list), lower Report pairs that share at least if they're short, and compare.

Partly. With imperfections allowed (for example, up to 2 imperfect words in a row with 80% matching), WCopyfind finds copying that was lightly edited: a few words changed, added, or removed. It doesn't understand meaning, so text that was thoroughly rewritten in different words won't match.

New documents are compared with each other and with the old documents. Old documents are compared only with the new ones, never with each other. Put the papers you're checking in the new list, and sources and past papers in the old list. See the guide.

No. It shows that two documents share wording, which you then need to judge. Quotations, citations, common phrases, assignment prompts, and shared sources all produce matches. WCopyfind shows you exactly where to look. See interpreting matches.

Word documents (.docx and older .doc), plain text (.txt), web pages (.htm and .html), PDFs that contain text, and internet shortcuts (.url) to web pages. It will try to find text in other files too, with no guarantees. If a file won't read well, save it as .txt or .docx from the program that made it.

Many PDFs, especially scanned ones, contain pictures of pages rather than text. You can see the words, but there are none for a program to read. Run the PDF through OCR (text recognition) software first. For PDFs that do contain text, WCopyfind reads them much better with the free pdftotext.exe placed beside it.

Yes. WCopyfind compares any language that separates words with spaces or punctuation, including Spanish, French, German, Greek, Russian, and many others. Choose the closest language in More Options so WCopyfind knows which characters are letters and punctuation. Languages written without spaces between words, such as Chinese and Japanese, don't work well. For plain-text files in other languages, save them as UTF-8 so WCopyfind reads every character correctly.

They work. WCopyfind 6 handles file and folder names in any language, including in its saved lists and reports.

WCopyfind is a Windows program. Mac and Linux users have run it successfully with Wine, and it runs in any Windows virtual machine.

No. It's a single program file: unzip it and double-click. To remove it, delete the file.

Windows SmartScreen warns about programs that aren't signed with a paid certificate. Click More info, then Run anyway. WCopyfind is open source, so anyone can check what it does.

An older command-line version, Copyfind 4.1.5, reads its instructions from a script file and can run thousands of comparisons unattended. It uses the same engine as WCopyfind 4.1.5.

Matching words is the number of words in phrases the two documents share exactly. % of A and % of B are those words as a percentage of each document's length. See what the numbers mean.

Yes. The pages print cleanly from your browser, and you can save them with your browser's Save as. To keep a whole report, copy the report folder. You can also select all the text in one document and paste it into a word processor or spreadsheet.

For example: Bloomfield, L. A. (2026). WCopyfind (Version 6.0.2) [Computer software]. https://wcopyfind.wfindapps.org