I've had to grade quite a few essay papers in the classes I've taught, and I've suspected some may have plagiarized but I never really pursued check on them because it would be too time consuming to check their sources and pursue any/all possible sources where they may have copied from.

What's the easiest way to check for plagiarism? Is there a search engine tool that one could use to upload a paper and check for it? I doubt it, but other than that, I don't know of any other way to check for it than to put in more effort than I have time for.

  • 14
    easiest way...google some sentences Commented Mar 8, 2013 at 22:57
  • 5
    I've always wondered what happens if I take the definition of an uncommon concept out of my dissertation and make a new Wikipedia page out of it. Does that mean that my thesis will automatically get flagged as plagiarized in future? Commented Mar 10, 2013 at 12:30
  • 5
    Ironically? Your students are looking at an easy way out of their work ... too! I mean, they at least search for their ill-gotten works - you didn't search for this or talk to colleagues, presumably. Or tell us what age, subject, institution size ... Despite all that, you got a good answer, why haven't you accepted it?
    – hunter2
    Commented Jun 25, 2013 at 8:51
  • 1
    From my experience of peer reviewing my friends who are ESOL, it is painfully obvious when they just copied and paste. And then Google pulls up whatever source they used.
    – Mallow
    Commented May 21, 2014 at 16:05

7 Answers 7


There are plenty of tools out there. The best 'seems' to be TurnItIn. It's costly so if the school won't pay for it, you might not be interested. My school does not so I found other options.

Here is a tool called WCopyFind that is very good at finding plagiarism when one student copies from another but it will not find something online. After collecting papers for several semesters it has been catching more and more and most students take the same easy way out.

There are other options if you search for online plagiarism checking but they are not as robust as this tool above...however to really see the benefits, you need to maintain a library of old papers to compare against. What I like about it (besides being FOSS) is that it is highly configurable (consider a match 6 words in a row, or consider a match 9 words in a row where 70% of the words match). It all runs local (since there's no internet search) so it's quite fast.

  • 2
    It's worth noting that TurnItIn also offer their services to students who can use it to iteratively hide their plagarism. This makes me extremely dubious about their reliability. Commented Jan 22, 2016 at 8:57

In my department/university we have access to some systems for checking for plagiarism but most of us end up using Google, believe it or not. The reasons are that the plagiarism systems (we have access to) seem to work on a limited subset of work and that Google is extremely easy to use. My suspicion is that the existing systems may be tailored to specific subjects and may be excellent within these. So I would simply say, test your suspected essay by inserting sentences or even larger (key) parts of paragraphs into Google and see what comes out.


You can also do it yourself using google. Pick a single idiosyncratic phrase from the manuscript and search for it in quotes. It is amazing how often you will find search results have that same phrase followed by and preceded by the same words as in the paper. If so, you have found plagiarism. I once found a term paper substantially ripped off from a MS thesis (from a small schol in Australia) using this technique.


If your school uses blackboard, d2L, or something of the sort...plagiarism detection (if that's what we can call it) is built into the system. For blackboard, the program is called safeassign. Students submit their papers through safeassign (I'm convinced that just telling them about this program cuts down on plagiarism), and then the program gives you a report (ie 23% plagiarized). A couple of great things about the program: it gives you the source where the student lifted the information and keeps a running database of papers so that students cannot use each others assignments. It makes the process totally objective, and you won't have to worry....the program does all the work. Good luck!

  • 3
    It's worth remembering that the report is only useful if you check what it is saying. For example, I just had a whole page flagged up - the cover sheet.
    – Jessica B
    Commented May 22, 2016 at 7:09

Some of the plagiarism tools do not seem to be effective against bilingual students who plagiarize and then translate the works with machine translation. It only takes 1 minute to catch:

  1. Select and copy a random sentence from the paper containing some rare words.
  2. Paste this sentence into an on-line translation tool, set to translate from English to the student's L1.
  3. Copy this output and search for it in your favorite search English.
  4. If the search preview finds a sentence word-for-word match, copy that address.
  5. Translate the whole address from that student's L1 to English and compare that with their paper.

Since most students who plagiarize are also lazy, many do not seem to bother with editing the translation, so I've caught many students who submitted papers in this fashion where the output from the Web translation service was identical to the output they gave me.


Recently, I had to check several texts for plagiarism, and I used a free plagiarism checking tool (you can google for one, there are a few that are returned). You just copy and paste text there and if it is copied from any published source the tool will detect it and provide you with the link to the source. That's how you can actually check the accuracy of references as well. Though the tools are not designed for academic purposes, it works well for checking any kind of papers.


Please note that some "free plagiarism checkers" will turn around and sell the papers that are submitted to them to other students. Be careful with their use.

I find TurnItIn to be well worth the cost. Even though students can check their own papers through the system, this is a GOOD thing because it teaches students what is plagiarized and what is not. If the student has to make adjustments to ensure that they aren't plagiarizing, isn't that what we want them to do?

  • Learning what minimal changes they need to make to hide plagiarism is undoubtedly a skill that will be useful outside academia, yes. These days, of course, they can simply ask an AI to rewrite it.
    – arp
    Commented Mar 29 at 4:39

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .