While the Internet has opened up an incredible opportunity for online learning and research, it has also allowed for the increased likelihood of plagiarized content whether intentional or not. Plagiarism is not only copying and pasting text directly from the source into your own writing, but also the copying of ideas (including paraphrasing where words, ideas or information have been changed into your own words so as not to resemble the original text) without crediting the source. Any words, including quotes or paraphrasing, as well as ideas that are not your own should be clearly marked in indented block text or quotation marks and sources should be properly cited. See more information for citing sources below.
To avoid plagiarism, make notes and citations as you write, give proper credit to sources, and finally, use a plagiarism checker to ensure that your work is entirely original.
Plagiarism checker tools can also help you to find out if anyone else has copied your content.
For most informal writing, it is acceptable to cite sources by either using quotation marks or indented block text and include the source in in-text citation and/or the end notes. To cite an online reference, one should include at minimum the author’s last name (or short title if there is no author), publication year and “Retrieved from http://URL”. For example: Author, A. (date). Title of document [Type of document]. Retrieved from http://URL
I have taken the time to test out a long list of free plagiarism checkers using a fabricated document with a large percentage of intentional plagiarism. There are a lot of other free plagiarism checkers out there, but I found many to be quite useless and so I have only added the ones that actually work well and are helpful. While they don’t all catch everything, they do pick up most plagiarisms. I found that running my document through a few of them to double check was helpful as a few of them picked up different things. Below is a list of the top 6 that I recommend.
DupliChecker is an accurate free online plagiarism tool for checking up to 1000 words. Each sentence is dissected, and all the source websites from where the content was copied are displayed. This checker works really well, although it only allows you to check 1000 words per day without registering (one way to get around this is to clear your history and try again or try a different browser). Registration is free.
Plagiarisma offers a limited free version using a copy and paste online option (2000 word limit), an entire URL search, or a file upload option. They provide a detailed, helpful report which includes sentences which are completely unique. You can add use the checker about 3 times without registering for free.
Viper is a free plagiarism scanner that requires installing software on your computer and registration. The software then requires you to login, upload your document, add a category and scan. Viper scans documents against 10 billion sources and offers side-by-side highlighted comparisons for plagiarism. I found the software to be accurate and although it missed a few of the plagiarisms that some other online checkers had picked up, it picked up several additional ones that all the other online checkers had missed. Note that Viper is available to Microsoft Windows users only.
SeeSources is a free online plagiarism checker for up to 1000 words. Copy and paste or upload MS Word, HTML or text formats and press ‘Start Analysis’. The results are helpful, though not as thorough as the previous checkers.
Paper Rater offers grammar checking, writing suggestions and an average plagiarism detection in the form of a percentage with only a few of the web pages which may contain content matching the document. Uploads are limited to 2000 words. You need to make sure you have chosen the optional plagiarism detection option before proceeding to ‘Get Report’. Although the feedback is not thorough, it may be helpful to do a quick check on the plagiarism percentage of the document.
To use this plagiarism checker requires a free registration. After you upload your document, PlagiarismCheck checks your document and after some time, emails you a link to a pdf report. If the link doesn’t work, as happened in my case, you can view the report online by logging in to their website. I found this checker to be relatively accurate, although it still missed some of the intentional plagiarism in my fabricated document.
I’d love to hear of any other checkers that you have used and can recommend. Please leave your suggestions and feedback in the comments below.