How do I check my research paper for plagiarism?

There are a number of tools available online that you can use to check your manuscript for plagiarism. IThenticate, PlagScan, Turnitin, Unicheck are some of the recommended plagiarism checkers that are currently available. However, all of these are paid tools with a varying fee. Alternatively, some professional editing services also provide a plagiarism check along with the option of manuscript editing.