Paper series duplicate checking system is a paper duplicate checking tool based on internet technology, which is usually used to detect the repetition rate of papers. However, credibility is one of the important standards to measure the quality of paper duplicate checking system. At present, the popular paper series duplicate checking systems in colleges and universities include paperfree, papertime, paperpass, paperYY and so on.

The paper duplication checking system compares the documents in the database with the papers submitted by users, finds out the similar parts, and then calculates the similarity rate. These comparison results and similarity rate are important basis for judging whether there is plagiarism in the paper. If the comparison database of the paper duplicate checking system contains enough documents and the comparison algorithm is accurate enough, then the credibility of the system is relatively high.

However, the comparison algorithm and database of each paper duplicate checking system are different, so the duplicate checking results of different systems may be different. PaperFree paper duplicate checking software compares and analyzes the submitted papers through a massive database, accurately discovers the potential plagiarism and improper quotation in the papers, and the first duplicate checking is free. Its online duplicate checking function realizes the modification and duplicate checking of the test paper, and it can be checked wherever it is changed; According to the actual modified sentences, there is no charge for the content that is not changed; Enjoy the wonderful experience brought by intelligent weight loss of paper.