The best three plagiarism checkers on the web

The growth of the Internet has meant that billions of web pages, books, journals and other resources are available to students in just a few clicks. Consequently, student plagiarism is now the biggest dilemma that colleges, universities and other learning institutions now face, threatening to undermine and call into disrepute the value of awards that those learning institutions confer. It is therefore no surprise that those institutions have devoted a great deal of time and effort into plagiarism detection.

As a student, you may have the best intentions to submit your own completely original work, but this doesn’t always happen. Sloppy referencing, careless paraphrasing and unintentional plagiarism (for example, cryptomnesia) can all land you in a world of academic trouble and sometimes result in you losing a place on your course. It therefore makes sense to take advantage of the good number of plagiarism checkers accessible on the web today, before you submit your work to be marked. Here, we review three of the best:

1. WriteCheck –

At the top of our list is WriteCheck – created for students by the makers of TurnItIn. TurnItIn plagiarism detection software is used by more than 15,000 learning institutions in over 140 countries across the globe and is the number one brand in the plagiarism detection industry.

The pros of WriteCheck are that it is one of the most comprehensive plagiarism checkers, checking against its database of 337 million previously submitted papers, over 130,000 published works and more than 45 billion web pages. When you scan your essay through WriteCheck, it doesn’t get added to their database, which means that you don’t need to worry about a match showing when your school or university later scans the work.

The cons are that when a match is identified, you won’t have full information about what source the content has been matched to – although usually you can figure this out from reviewing your own work and notes. WriteCheck is also paid software – a single paper of up to 5,000 words will cost $7.95 to scan, with three resubmissions permitted.

2. SmallSEOTools –

You might be surprised to see that our second choice of plagiarism checker is actually a free online tool that consists of no more than a box to paste in text on the screen. Surprisingly, this tool is incredibly effective. It works by breaking up your text and sending it off to Google in chunks, and then reporting back with an overall match score. Because Google is extremely good at matching content, even when it has been changed around a little, the SmallSEOTools checker actually performs better than WriteCheck and as a bonus, you’ll learn the source of any matching content which makes it easier to correct.

The cons of this tool, and the reason it isn’t number one on our list, is that the resources it scans against are limited to sources publicly accessible via Google. WriteCheck by contrast scans against sources that aren’t available through web search, including journal databases and students’ papers. The latter is extremely valuable since students frequently quote from paper sources (e.g. popular academic books), which means that the resources available to the WriteCheck scanner go beyond online content only.

3. Viper plagiarism scanner –

Our final choice is Viper which unlike the above two online options, is free downloadable software. Viper is very easy to use and scans are unlimited. Once you’ve downloaded and installed the software, you simply create an account, log in through the software, click ‘add’ and then ‘scan’. The pros are that it’s free, it’s quick and the report is easy to understand.

The cons are, as for the SmallSEOTool scanner, it only scans against web resources which makes it far more limited in scope than the WriteCheck scan. We also noticed that the original text and found text windows included a lot of Microsoft Word mark-up in our tests, making them rather difficult to read. In addition, the website notes that if you use the plagiarism scanner, you grant the company a licence to use a copy of your essay on one of their websites after 9 months have passed. This could result in an accusation of plagiarism from your college, university or learning institution if they choose to rescan all of your work at the end of the course, as many do.


There are many free and paid plagiarism checkers on the web and making use of them is a good idea to avoid accidental plagiarism and its dire consequences. However, for free plagiarism checkers, you need to read the small print and be satisfied with the way that the website intends to use your work in the future, if at all. You also need to be aware of the limitations of the software – to date, no plagiarism checker has been able to detect where written work has been completely reworded from an original source. Therefore, the software cannot tell you if your work has been heavily paraphrased without giving proper credit, or if you have relied too heavily on one or two sources which can still be regarded as plagiarism even if you have not directly borrowed any material from those sources.

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