This tool will compare two articles and show you which parts of the articles are duplicated, as well as give you the percentage of duplication within the articles. Only duplicate phrases of 3 or more words will be highlighted. The reason for this is that search engines cannot detect duplicates using one or two word phrases without an enormous number of false positives, so it's 3 or more word phrases you should be concerned about. http://thebestspinner.com/compare/ I'm sure many will find this useful. For those who have The Best Spinner 3.0, it also contains the same functionality in a downloadable desktop-based software. Enjoy!