Free Online Plagiarism Checkers and Duplicate Content Detectors

I have rounded up the most powerful (free!) online plagiarism checkers to prevent you from duplicating or (accidentally) plagiarizing text. Of course, you can use these same plagiarism detectors to identify plagiarists who are stealing your content or republishing your articles without your permission. I have thoroughly tested each of these plagiarism checkers to make sure: 1) they actually