free plagiarism check

Some of the advanced originality detectors, like Unicheck, use real-time web index, meaning that a user receives a more accurate similarity percentage.
Search across 40B+ web sources and open access databases

How about an option for sharing the plagiarism report generated? Would you like that right INSIDE the tool, too? Well, we got you covered!
And that is why we created the Plagiarism Checker by Small SEO Tools.

Furthermore, our tool displays the result in front of the user in merely a few seconds, which outweighs all other available plagiarism software. Besides, our tool respects the security and privacy of the users. Hence, you can use our online plagiarism checker without having any privacy concerns because whatever type of text you enter, it vanishes from our database as soon as checking is done.
Just follow the following steps:

Finding out that you’ve accidentally infringed on another’s work the night before your assignment is due can leave you scrambling to rewrite sections of your paper, update your citations, and modify your bibliography at the eleventh hour.
This is a fact that is known widely enough that it is considered common knowledge and does not require a citation.

References:

http://smallseotools.com/plagiarism-checker/
http://searchenginereports.net/plagiarism-checker
http://www.bibme.org/grammar-and-plagiarism/
http://www.thoughtco.com/argument-essay-topics-1856987