how to track text online?

[Sarah]

like, when we write an essay, the teacher makes sure you didn't just copy it from some site. She can calculate how much is copied. Do you know a site like this? (If there's too much copied, i fail.)

[Salem]

Try the links below, be warned though, there nowhere near as comprehensive as most plagiarism checkers used by educational institutions.

http://smallseotools.com/plagiarism-checker/
http://plagiarisma.net
http://scanmyessay.com/plagiarism-test.php

[?]

you can go through duplichecker.com which are designed to check, how much part of your article copied from, which sites.