Generally speaking, the first draft of the paper will be checked. This is because before submitting the paper, the school or periodical will ask the author to submit an original certificate. Duplicate checking software can help the author check whether there is plagiarism or improper citation in the paper, thus ensuring the originality of the paper.

If you need to use duplicate checking software, you can choose some cheap and regular websites for duplicate checking, such as FreeCheck and PaperFree.