The best tool available till date to check the duplicate content online.With Copyscape you can easily find out the duplicate content. Copyscape is trusted by millions of website owners worldwide to check the originality of their new content,prevent duplicate content, and search for copies of existing content online.
With Siteliner you can easily check the duplicate content.More over it is not only to check Plagiarism even you can check broken links,xml sitemap,internal page rank and many more by using this tool.
3)Smallseotools –Plagiarism Checker
Plagiarism checker is free tool to check the duplicate online for free.To check the duplicate content just you have to copy the content and paste it in the box.Results will be displayed with in seconds.Many bloggers around the world choose this tool to check the originality of an article.
Plagium is a tool to check the duplicate content online for free.Just copy the content of your article and paste it in the box. Plagium provides search over option i.e we can search the web,news and Social Networks for the duplicate content.Even we can check the content by the check url option available in Plagium.