I reviewed 7 free plagiarism checkers for students. And in my opinion, the best free plagiarism checker for students is Quetext. It’s got a high-quality dashboard as good as any paid tool. It also detects a decent amount of plagiarism.
Some other decent tools that get an honorable mention are Duplichecker, plagiarismdetector.net and Small SEO Tools.
Here are my overall results:
|Plagiarism Checker||Rating||Plagiarism Detection Ability||User Experience|
|3. Plagiarism Detector||7.5/10||High||Medium|
|4. Small SEO Tools||7/10||Medium||Medium|
|7. Paper Rater||Did not Provide Results||Low||Low|
A Word of Warning
Beware that free plagiarism checkers are no where near as good as the plagiarism checkers that I use as a professor. Your teacher probably has access to a quality plagiarism checker like Turnitin, which will detect plagiarism not only from the web but also:
- Journal articles and
So the best thing you can do is learn to paraphrase properly to avoid the possibility of plagiarism altogether.
Below is my full review of all 7 free plagiarism checkers.
How the Test was Done
To conduct this test, I wrote a 470-word mini-essay on Globalization. I just whacked it out in one short sitting, so it’s not referenced or of the quality I’d submit to a university. But it was enough for the test.
Then, I went online and found some sentences that I could cut and paste into the piece. The idea here was to see how well the plagiarism detectors would pick up the sections that I had plagiarized.
Here are some examples of the plagiarized sentences:
… there have been some serious downsides of globalization. Economic globalization impacts the environment and sustainable development in a wide variety of ways and through a multitude of channels. The enormous expansion of …
… many blue collar workers have felt disenfranchised and left behind. Globalization has not been good for working people (blue or white collar) and has led to the continuing deindustrialization of America …
Overall, 4 sentences and 74 words of the essay were directly plagiarized. That’s 15% of the total text. Then, I pulled out 7 different free plagiarism checkers and ran the piece through the plagiarism checkers to see which ones would pick up the plagiarized text.
Here are the results.
Best FREE Plagiarism Checkers for Students
Quetext.com has a beautiful interface. Simply go to their homepage and paste your text to get started. Once you click ‘check plagiarism’, it will ask you to sign-up to get your results. I recommend doing this. It’s worth your while.
Once you’re logged in, the dashboard is very clean and high-quality for a free tool. In fact, it feels a lot like the industry-leading (but expensive) Turnitin dashboard.
The text is shown in the middle of the piece, with the sections identified as plagiarism underlined. You can click on each identified plagiarism section and the right-hand column will show you the original webpage to see the highlighted similarity in its original context:
Often, the identified potential plagiarism isn’t anything to worry about. The similarity might be just a coincidence, in which case you can leave it. At other times, it’s clear that the original source and your copied section are too similar and it’s worth changing the text.
Overall, quetext identified all 4 of the plagiarized sentences. It also found 4 sentences that I hadn’t plagiarized, but were very similar to some source texts online. For two of them, I would have changed them because the similar webpage also discussed globalization. For the other two, it was complete coincidence and the similar webpage wasn’t even talking about globalization at all, so I didn’t find them to be too problematic.
How does a Teacher Assess if I’ve Plagiarized?
Your teacher will check the source text, just like I’ve done above, to see if the similarities are of concern. There are regularly false positives (for example when the source text isn’t even about globalization), so just like your teacher will, you need to check the suspected plagiarism and assess whether the similarity is coincidence or too much of a similarity for comfort. It’s common for tools like quetext to return a plagiarism score of 15% – 20%, with all of this being false positives that you don’t need to worry about.
One thing I do wish Quetext allowed you to do is to make edits in their dashboard. It would be good to get those sentences that were plagiarized, re-word them within the dashboard, and then re-run the check. This may be a feature in the PRO version, but of course, this is a review of FREE features of each plagiarism checker.
Duplichecker was quite easy to use and, while plastered with ads, could be used without any problems. The report shows the highlighted plagiarized sections on the left hand side and the matched sources on the right hand side:
This interface was better than many of the others that I reviewed here. You could see the plagiarized sentences in context on the right-hand side and an estimated percentage of similarity to the source.
Duplichecker beat Quetext by finding all 4 plagiarized sentences and no false positives. But, the source webpages that they identified were mostly from coursehero, which was not the true original source. Coursehero is simply a database on student essays, so in reality it just found other plagiarized essays that other students had written! Nevertheless, it’s good enough to find sentences that are similar.
Another thing that I found a little annoying was that Duplichecker has a ‘make it unique’ function that spins the text to make it unique. DON’T DO THIS! It makes the text awkward and sometimes illegible.
Plagiarismdetector.net is very similar to Duplichecker, to the extent that I did wonder if they were using the same technology to generate their results. It also has a very similar layout with the text on the left hand side and snippets of the plagiarized sources on the right:
I did notice, though, that after analysis the paragraph formatting had been collapsed. It turned my essay into a big wall of text that I found difficult to navigate. Keeping the break points of paragraphs would have been helpful.
Also like Duplichecker, you couldn’t click on the highlighted sentences to generate a highlighted pane on the right with the original text highlighted in its original context. The lack of this feature across all but Quetext really did bother me personally.
Again, the coursehero results (aka other student essays that plagiarized the original source) were shown instead of the true original source. I would like to see coursehero deprioritized, so if plagiarism was detected from coursehero and another source, the other source is displayed instead of coursehero. The same would go with the UKEssays site, which is another database of (often plagiarized) essays that students often.
Overall, plagiarism detector identified all 4 of the plagiarized sections and generated no false positives.
4. Small SEO Tools
Small SEO Tools has a plagiarism checker designed for online publishers and bloggers rather than students, but we can make use of its power for any text, really.
The first thing you’ll notice is that you have to navigate between the ads to use the tool. Of course, it’s a free tool, and the owner of the tool needs to pay the bills somehow, so I don’t hold this against them.
You can paste your text into the search bar or even upload a document to be checked. Then, tick the Captcha to prove you’re human, and click ‘check for plagiarism.
One thing I really like about the Small SEO Tools plagiarism checker is that it provides a really nice to use sentence-by-sentence analysis, as shown below:
When you click the red ‘compare’ button for plagiarized sentences (as shown above), it will drop that sentence as a quote into Google and display all results:
This can be nice because you can see how many different sources have all used that same sentence, and dropping quotes like this into Google is something I definitely do when I suspect one of my students has plagiarized.
But again, Quetext won when it came to user interface because they display the results within the dashboard, allowing for a quick and easy check without having to switch tabs.
Overall, Small SEO Tools found 3 of the 4 plagiarized sentences, and gave no false results.
1text is a clean, basic plagiarism checker that doesn’t require you to login to get your results. Simply go to 1text.com and paste the text you want to check into the search bar:
When you click ‘check for plagiarism’, the check does take a little while to load. That’s because they give priority to people who sign up, so you might get a queue position and you will have to wait:
1text will look at three things: word count, grammar and spelling, and plagiarism. For our purposes, we want to focus on the plagiarism checker.
Unfortunately for this text, they didn’t find any of the four plagiarized sentences:
This was disappointing because in the past I have found 1text to be quite good at identifying plagiarism.
But, for demonstration purposes, I decided to feed an article entirely copied and pasted from a few different blog posts into 1text. I wanted to show you how the results show up. Here, I took a blog post on ‘how to write an introduction’ and fed it through the plagiarism checker. It correctly identified the whole blog post as plagiarized and pointed me to the copied sources:
However, unlike Quetext, it didn’t provide the dynamic functionality to click on a highlighted section and show me which sentence was taken from which source. So in this sense, there was a need for a lot more detective work for 1text. When it comes to user experience, Quetext won out big time.
Plagium is a premium service but allows for light checks for free without signing up. You will be able to conduct a quick search for free, but the ‘deep search’ requires a login.
From what I can tell, the deep search costs 8 cents per page. I’m not sure if you could get a few for free before having to pay:
So, I did the quick search! The quick search on plagium identified 0 of 4 of the plagiarized results.
I wasn’t satisfied with this, so I did another quick search with some obvious plagiarism going on. This time, Plagium did identify multiple results.
For Plagium, the plagiarized sections are not highlighted. Furthermore, it’s not placed side-by-side with the identified source text. Instead, it’s simply placed in a list below:
So, overall, I wasn’t particularly happy with Plagium. In my experience, it was a third-tier level of user experience for me and a lot of detective work would need to take place to identify the plagiarism, even if the tool finds it in the first place (which is clearly not guaranteed).
The paid tool may be more user-friendly, but of course, this review is of the free features only!
7. Paper Rater
Paper Rater failed to find any of the four plagiarized sections. So, I stuffed a bunch more clearly paraphrased text from sources like Forbes and Wikipedia. And it still didn’t find any plagiarism. So I stuffed even more plagiarized text in. And it still didn’t find any plagiarism:
I was very surprised by this. So, I don’t think I’ll be going back to Paper Rater any time soon.
Overall, I was most impressed with Quetext. Even though Quetext did find a few false positives, I would prefer to get a thorough test that generates false positives than a tool that doesn’t find any results at all. Quetext also had the most professional dashboard and user experience.
In the second tier of free plagiarism checkers, Duplichecker and plagiarismdetector.net get honorable mentions. They both identified all the plagiarism and no false positives. Their interfaces were quite good, but still not as user friendly as Quetext.
I also didn’t mind Small SEO Tools for its simplicity.
For the others, I personally would take a hard pass for various user experience problems, as well as their failure to find plagiarism in this test.
Dr. Chris Drew is the founder of the Helpful Professor. He holds a PhD in education and has published over 20 articles in scholarly journals. He is the former editor of the Journal of Learning Development in Higher Education.