Since there is no guarantee that the original content of your manuscript might not be copied and sold to others before it is published by you, I discourage using any free-software-checkers for plagiarism; some of them are betrayers.

If I were you, I prefer using my own words instead.

Kindly, could you please see the following warning that is related to this valuable question?

https://www.researchgate.net/post/Are_free-software-checkers_for_plagiarism_trustable_and_faithful

You can try this one

http://www.mediafire.com/file/y9e0owyhwy8572t/Plagiarism_Checker_X_5.1.4_Pro.rar/file

Thank you very much

Although it's not downloadable software, here's an online plagiarism checker that's pretty good. They claim there's no length restriction but I found that I had to divide my document into two parts because it was too long; if I remember correctly, the limit is about 19,000 characters. Still, that's better than all the other free online checkers I've seen which typically have a thousand-word limit.

https://studyclerk.com/online-plagiarism-checker-with-percentage

Thank you very much

Since there is no guarantee that the original content of your manuscript might not be copied and sold to others before it is published by you, I discourage using any free-software-checkers for plagiarism; some of them are betrayers.

If I were you, I prefer using my own words instead.

Kindly, could you please see the following warning that is related to this valuable question?

https://www.researchgate.net/post/Are_free-software-checkers_for_plagiarism_trustable_and_faithful