Plagarsim check

Question

Could your own preprints of the same paper on arXiv and other sites be considered as plagiarism when the journal checks this paper using, for example, Turnitin plagiarism program?

Answer 1

I suppose that an automated system might flag it, but a person would certainly recognize what happened.

However, note that some journals won't accept a paper that has appeared on arXiv or elsewhere prior to submission. Some will place a copy there after acceptance, but they want to control access themselves.

But in any case, it isn't plagiarism.