My graduate school doesn't offer TurnItIn facility.
All tools available online charge money.
How can a I check plagiarism free of cost before submitting my research paper?
My graduate school doesn't offer TurnItIn facility.
All tools available online charge money.
How can a I check plagiarism free of cost before submitting my research paper?
Ask yourself a simple question: Did you plagiarise?
Assuming the answer is no, there's no need to check whether you plagiarised.
Perhaps these sources may help (I found them after doing some searching around), though to use them for free you may need to copy and paste your paper in chunks:
I think Grammarly also has a plagiarism detector, if I recall.