Plagiarism Checker Online Service Review – Top Ten Plagiarism Checkers

The Different Tools Available to Battle Plagiarism

When writing professionally and for academics, it is critical to ensure that all written copy is original, and using a plagiarism checker is the best way to detect unoriginal or copied text. There are many different plagiarism checkers on the web, but figuring out which ones are the most effective is a little difficult as they all contend to be able to do the same thing. In reality, some websites only detect plagiarism from top websites like CNN or Wikipedia, but fail to pick up published blog articles and lower-ranking google search results. 

In the past, plagiarism software was mainly downloadable and run locally. Today, plagiarism checkers can be found online as SaaS (Software as a Service). These are online web services, so no local software is required. Some services will charge money for each search, some charge for a monthly or yearly subscription. Others are free of charge. There is an abundance of such tools on the internet, but not all are accurate or worth the money.

Details About Our Testing Plagiarism Checker Process

To keep the test fair, we used the two pieces of original text, that we called Test A and B. Test A’s text is taken from a CNN article published 7/5/2017. It was originally located on the CNN website and one other website. The text for Test B comes directly from a unique article on dated 04/08/2017. Both pieces of text have been in the google search for some time. If the plagiarism tester software is effective, it will pick up both Test A and B as plagiarized. Below are the plagiarism test search results:

Name of ProductCostTypeTest 1
Test 2
NotesFinal Grade
PrepostseoFreeText OnlySuccess
PrepostSEO requires an account for multiple searches, but the use of "incognito mode" on the browser bypasses this need.A+
PlagiumFree/.04 per pageText OnlySuccess
Allows for search customizations and reliable resultsA
CopyLeaks$0-$1,100/monthText OnlySuccess
CopyLeaks provides a few free searches per month, but requires an account. Additional searches will need to be paid for, but the cost comes down the more there are.A-
CopyScape.05 / searchText and URLSuccess
Plain interface without bells and whistles, but overall a good option, with reliable results. This service is also one of the few that allows you to use links instead of just text.B+
The PenstersFreeText OnlySuccess
ThePensters offers a limited number of free searches per user. Use “incognito mode” on your browser for unlimited searches.B
Grammarly$140/yearText OnlySuccess
Grammarly requires an account and a subscription to view results, which were less than compellingB-
Unicheck$10/monthText OnlySuccess
Good results but and extremely slow serviceC+
PlagiarismaFreeText OnlySuccess
The site is riddled with advertisements, but it finally works if you can stick with it. It's a less than stellar interfaceC
SmallSEOTools.comFreeText OnlySuccess
The interface is riddled with ads that can make finding the right button to click difficult and confusing. It failed on one of the tests, so its overall results are poor.C-
ViperFreeText OnlySuccess
Viper required an account, and did not allow for text to be directly copied into the interface, instead requiring a file upload.D
SearchEnginerReportsFreeText OnlyFail
Confusing interface and inaccurate results.F OnlyFail
SEO Tools Centre was both slow and inaccurate. A thumbs down on this one.F
Top ten plagiarism checkers
Top ten plagiarism checkers

The Best Plagiarism Checker: Results

The winner of the title of best plagiarism checker is PrepostSEO, with Plagium at a close second. Prepost comes with quite a few benefits. The results are accurate and fast, and any plagiarized text is clearly highlighted. In addition to the plain plagiarism checking software, the website offers broken link checks, a tool to compare two articles for plagiarism, HTML plagiarism checks, and SEO services. Though the website does require a subscription after a few searches, using incognito mode bypasses needing to pay. Plagium is another great option, and offers a limited number of searches for free. Like Prepost, the need to pay can be easily bypassed through the same method of incognito browsing, but a “deep search” is only available for a fee. CopyScape and CopyLeaks yielded similar results, but CopyLeaks has a better interface.

More Results

ThePensters has a decent plagiarism checker, but the website is clearly meant for its essay writing services, not plagiarism. Grammarly is the heaviest advertiser of all the plagiarism checkers, but is not recommended, because while entering copy for plagiarism verification is free, the user must pay to view any results, which feels like a bait and switch. People don’t mind paying money to ensure reliability of their plagiarism checkers, but $140 a year for Grammarly is pricey.

Even More Results From Our Plagiarism Checker Tests

Some plagiarism checkers were riddled with ads that made navigating the website somewhat difficult. Search Engine Reports, Plagiarisma, SmallSEOtools all had this issue. Other websites required an account to even look at the plagiarism checker, such as Viper and Unicheck. Some websites surprisingly failed at both tests, and were unable to even pick up CNN. SEO Tools Centre and SearchEngineReports both failed all the tests. SearchEngineReports was an interesting case in that it did note that the text from Test A was copied, but it failed to indicate the correct website.

Michael Rogers

Having never been a member of the 657 crew and still a frequent guest at the Jolly Sailor, Mike likes to travel back to his old stomping grounds once in a while. Rogers has been writing for twenty years about things that really don't matter for such publications as Good Housekeeping and The Radio Times. Married with two dogs and a cat, he will often be found at his desk looking for writing inspiration in the most random places, often in the waste paper basket for something he wrote last week.