Four free online plagiarism checkers


Four free online plagiarism checkers

IJNet | November 17, 2015

“Detecting duplicate content online has become so easy that spot-the-plagiarist is almost a party game,” former IJNet editor Nicole Martinelli wrote in 2012. “It's no joke, however, for news organizations who discover they have published copycat content.”

When IJNet first ran Martinelli’s post, “Five free online plagiarism checkers,” two prominent U.S. journalists had recently been caught in the act: Fareed Zakaria and Jonah Lehrer.

Following acknowledgement that he had plagiarized sections of an article about gun control, Time and CNN suspended Zakaria. Lehrer first came under scrutiny for "self-plagiarism" at The New Yorker. Later, a journalist revealed Lehrer also fabricated or changed quotes attributed to Bob Dylan in his book, “Imagine.”

To date, Martinelli’s list of free plagiarism checkers has been one of IJNet’s most popular articles across all languages. It’s clear readers want to avoid the pitfalls of plagiarism, so we’ve updated the post with four of the best free online plagiarism checkers available to anyone, revised for 2015:


Grammarly gets points for its clean, easy-to-use interface and its efficacy as a plagiarism checker, which compares your writing to more than 8 billion web pages. To check any piece of writing for possible plagiarism, simply drag and drop a file or copy and paste your text onto the web page. Best of all? Grammarly isn’t just a plagiarism checker. The site also checks for spelling and grammatical errors and suggests optimal vocabulary words, allowing you to improve your writing. Grammarly is only available in English, which is one potential drawback for journalists who work internationally.


NoPlag is another great plagiarism checker that compares your writing to articles published online to detect possible cases of plagiarism. To use NoPlag for free without an account, you’ll be able to perform five plagiarism checks per day, with text samples up to 500 words in length. By registering for a free account, you get 20 checks per day with up to 800 words.

Plagiarism Checker

Plagiarism Checker allows you to check writing samples up to 1,500 words in length for plagiarism. If your writing gets marked for potential plagiarism, you’ll be able to review the exact places in your writing that match with content found online.


Want to make sure your website or blog doesn’t plagiarize? Simply copy and paste your URL into CopyLeaks, which uses cloud computing-based algorithms to weigh your content against trillions of websites. CopyLeaks is compatible with any language.

Main image CC-licensed by Flickr via Andres Moreno.



From my experience, free tool

From my experience, free tool doesn't mean good tool. I used to check papers for plagiarism using free online checkers but the quality of their reports was extremely poor. Now I'm using Unplag, it's not free but this price worth paying for results. As a teacher, I care about the quality and safety of tools me and my students use.

It is important for journalists to be truthful

Great list of tools, haven't heard about some of them yet. 
The journalist should care about the accuracy of his writing, and don't forget to cite the necessary parts of his articles. I use this plagiarism detection tool before my articles go live. 

It's fast and accurate, and it's never let me down.

As an editor and part time

As an editor and part time high school teacher, I beg to differ with officials who claim college students 'do not know' they are plagiarizing.

They know. They just think they'll get away with it by pretending innocence. Hey, it's worked before.

Every single year, since they're in about sixth grade, they are told (countless times) what plagiarism is and why it's wrong. In English classes and in the library, students spend an entire class or sometimes several practices not only learning about what constitutes plagiarism specifically, but also in doing exercises and models of practical examples of plagiarism. They are told repeatedly that if they plagiarize - which is x, y, & z - they will earn a 0.

The problem is that they then get away with plagiarizing--particularly when they loudly protest they 'didn't understand.'

In my 11th grade English classes, I caught six students grossly plagiarizing--this is without a program like, since my school is poor. I simply googled suspicious passages and up would pop interent sites proudly calling themselves 'echeat' or some other rather direct name.

Let me say it again: They know what they're doing. They just want to get away with it. And they do.

I failed these students (0 on their research paper), as per school policy and called the parents. I was lucky, because all six parents supported me. But plenty of parents race to the rescue of litttle Johnny or Suzy and begin a campaign to harrass and intimidate, calling the superintendent if necessary. Almost always, the superintendent or principal caves into the demands of the parents. The parents use whatever tool works to get what they want (just like their kids!)---they attack the teacher, accuse the teacher of incompetence or favoritism or racism or (fill in the blank).

Most teachers conclude it's not worth the risk to give the students a 0 because they know administration won't support them if the parents go on the attack. Untenured teachers could lose their jobs from such an attack (this is why tenure is so important, but I'm off topic here).

In this climate, students quickly learn that they can and do get away with plagiarism. Most of the times they are not caught because teachers have quickly learned it's not worth the risk to catch them. If they are caught, their parents go on the attack. Students claim they 'didn't understand' event though they've had the same plagiarism speech for six years or more.

Of course, it is grotesquely unfair to the students who actually do the work. But to be cynical, this is the model our entire economic system is based on: some people work their butts off, and others cheat their way to the top; and if they're connected enough, they succeed.

The pattern continues into college. Why wouldn't it? It worked before, why not again? I've taught in college too, and believe me, we have the exact same exercises on plagiarism. Sadly, many college officials in many colleges have the exact same lack of support as high school officials. Johnny or Suzy complains loudly that they 'didn't understand' and the officials go belly up. Many professors - many of them adjuncts with zero job security - are under a great deal of pressure not to follow their stated policy, which is a 0 on the paper at the very least.

So the lesson these students learn paradoxically goes hand in hand with plagiarism itself: milk the system, cheat, bully, use any shortcut possible, since there is no intrinsic value in learning. The only value is the short term A. They have a future in Wall Street.


O Grey, an and editor and Moorpark hich school teacher

Story from my life that shows which tools are better

Thanks for recommendations! I've tried to use free plagiarism checkers but it seems to me they do not work well. I can give you an example. Once, I wrote an essay and handled it to my teacher with a dead certainty it's perfect. To be honest, this wasn't written by myself, I order it in one guy from my university. After he sent me a finished essay, I checked it for mistakes and plagiarism with free online services. Those tools confirmed everything was OK, so I passed it with peace of mind. But a few days later my teacher put me a really low grade and said she was disappointed. I was shocked cause I was sure the grade must have been excellent. My teacher said she detected 50% of plagiarized content. This seemed unbelievable so we decided to check it together. She used fee-paid resource PlagiarismSearch ( and it detected plagiarism for true. Since then, I use only paid plagiarism checker because I'm sure they work much better.

Thanks for a good list of

Thanks for a good list of plag checkers. Being a college student, I found that these tools help a lot. Sometimes happens my paper are not 100% unique so using this tools I can know for sure what I give my professors. Another way to avoid plagiarism is to use essay services. They can write unique content and there is no need to care about stolen sentences. At my blog, I share some other ideas how to deal with plagiarism. 


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