Duplicate checking software is usually compared with academic databases and periodical literature to determine whether the content in the paper is similar to the existing academic research, including continuous strings, phrases, sentences or paragraphs. This helps to find possible plagiarism.

Some institutions or schools may use their own databases to compare the similarity of papers, including previously submitted papers, research results or other academic works. This helps to detect whether the same or similar content has been submitted multiple times.

In addition, when the paper is duplicated, the duplicate checking rate of the paper is that the duplicate checking system calculates the number of duplicate words in the paper through an algorithm. The first draft of the paper can choose two duplicate checking systems, paperfree and papertime, and the first duplicate checking is free. The detection scope of papertime system covers all Chinese categories, including philosophy, economics, management, law, social science, education, literature, art, history, science, engineering, agriculture, medicine, politics, military science and so on. At the same time, English and some small language articles can also be detected.