Generally speaking, in addition to the 1-2 free duplicate checking opportunities provided by the school, there are also some third-party duplicate checking websites in the market that provide free duplicate checking services for papers, such as paperfree, Papertime, paperday and so on. These regular duplicate checking official website usually require users to register and fill in relevant information, and then provide free opportunities to check the number of words.

Some institutions or companies may also provide free paper duplicate checking services, such as some academic journals and publishing houses. These institutions or companies usually ask users to provide relevant information about papers, and then check them for free.

It should be noted that the free paper duplicate checking service usually limits the number of words or duplicates. If you need a more comprehensive and accurate duplicate checking service, you may need to purchase the corresponding paid service. In addition, duplicate checking can not completely guarantee the academic integrity of the paper, but also requires the author to consciously abide by academic norms and moral standards.