copyscape.com is the best tool to know if the content has a duplicate or not. You can use it for free or paid.
This is an excellent tool. Highly recommended.............. http://smallseotools.com/plagiarism-checker/
Hi Patel, Copyscape is a most popular & trusty tool to check duplicate content and it so much effective. You can use duplicheker.
There is a list of FREE online plagiarism checkers I have posted here: https://forums.digitalpoint.com/thr...st-of-free-alternatives-to-copyscape.2700629/. It might be useful. There are many, but I sincerely request NOT to go for spun content. Such content has no value and is rejected by Google bots for redundancy. It will badly affect your PR. Hire a writer instead. If there are financial constraints, do it yourself. But please DO NOT go for spun content.