PaperRater Plagiarism Checker – Review by Nancy Johnson

Powered by Artificial Intelligence, PaperRater combines proofreading and plagiarism detection. You can inspect documents for grammar and spelling mistakes, get writing suggestions and even have an essay automatically graded – and all of that for free. The plagiarism finder, however, has recently become a part of a premium subscription, and there’s no free trial either. Luckily, you don’t need to pay just to test the tool out, as I’ve already done that for you.

Paperrater interface

Educators often prefer PaperRater because of the security concerns. This service removes most papers almost instantly after they have been uploaded and doesn’t scan new works against them. Instead, it uses the Internet as its database and leverages search engines’ APIs for that. Every document is compared against more than 20 billion web pages indexed by Google, Yahoo, and Bing.


The Premium plan costs $14.95/month or $7.95/month (if paid $95.40 for a year). With the Premium account, users can check documents for mistakes or unoriginal content. With the first option, you get a detailed report that contains spelling and grammar suggestions, word choice and style information, and an automatic grade. The grade shouldn’t be considered as final, as it only evaluates the work’s structure, but not meaning.

Paperrater suggestions

Though both free and premium users can take advantage of the proofreader, the results can be different. Thus, in my research, the same text generated different grammar and spelling suggestions. The readability indices summarizing a paper’s complexity are available under the premium plan only.

Testing results

But let’s get back to plagiarism. PaperRater flagged a passage copied from Wikipedia as 100% unoriginal. At the same time, when I submitted another copied passage, this time from an online PDF, it gave it 91% originality. The tool did find the matching source, but clicking on it lead me to the whole PDF file where identical parts hadn’t been highlighted. Paraphrasing and character replacement are two more tricks that make PaperRater (and its users) believe a submitted work is unique.

Paperrater report

Depending on what type of a check you perform (proofreading or plagiarism), you will get a corresponding report. Both reports are available in a printable version, but cannot be downloaded.

Final score

Paperrater analysis

In my research, I gave PaperRater 2/5 for detecting plagiarism in a text taken from an HTML source but marking other copies as original. You can see how the tool’s score, features, and price compare to those of its competitors in my overview.


PaperRater found matching sources for most of the submitted works. However, the originality scores may be confusing, as they don’t always reflect reality. You may want to keep an eye on the tool though, as its developers plan to be releasing “a second generation solution” shortly.

1 Star2 Stars3 Stars4 Stars5 Stars (1 votes, average: 5.00 out of 5)
97% Unique
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