Whether you are doing it for your own research or for others’ works, manually checking for plagiarized content is time-consuming and inefficient. Plagiarism software eases this burden for students and teachers by automating the process.
Such software can come with algorithm-based detection features, plus useful capabilities like writing suggestions and citation generators. However, you will often find these features in paid plagiarism checkers that require a hefty fee. This can be a problem if you are a student on a budget or if you are a teacher and your school does not subscribe to a plagiarism detection software.
The alternative is to use free plagiarism checkers like the ones below to check one’s work. To come up with the list, we employed a simple test of copying and pasting content from the PDF copy of an academic journal. The free plagiarism checker tools were then ranked primarily based on their level of accuracy in detecting the unattributed content. Secondary considerations include additional features like character or word count limits, file formats supported, reporting features, and citation generation. Keep on reading to know which ones made the cut.
What are the Top Free Plagiarism Checker Tools?
- Search Engine Reports
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- Pre Post SEO
Academic institutions often have clear-cut zero-tolerance policies for students caught plagiarizing their research and essays. This is because of the widespread incidence of plagiarism among higher education students, which presents an increasing concern for school administrators and faculty who are serious in defending academic integrity (MacLennan, 2018). However, it is a bit different for research professionals submitting their work to journals for publication where even self-plagiarism is not allowed. Self-plagiarism is when the author reuses previously published content and passes it off as new without telling the reader where the work previously appeared (Roig, 2011).
In a plagiarism study by Enders et al. (2004), they found that only 19% of journal editors had formal plagiarism policies within their organizations. As such, journal editors can respond to instances of plagiarism in a number of ways. In the survey, 70.9% said that notifying the original author as soon as possible is definitely an appropriate response to a clear case of plagiarism (Enders, Walter & Hoover, Gary, 2004). However, 42% said informing the plagiarists’ dean and other superiors is not likely an appropriate response. Moreover, 51% said that informing the public about the incident is also not likely an appropriate response.
Another plagiarism study by Karabag & Berggren (2012) tried to relate the issue to papers that were retracted due to intellectual dishonesty. They observed that science journals are more active in retracting papers than business and economic journals. For instance, they found more than 700 papers retracted from ScienceDirect, a database of scientific journals from 1985 to 2012. In contrast, they only found seven retraction notices from Emerald Management Journals. This led them to conclude that “the leading business and economics journals’ response to academic dishonesty and plagiarism has been slow (Karabag and Berggren, 2012).”
One prominent case of plagiarism involved Harvard Law professor Charles Ogletree. He admitted to copying word for word six paragraphs from the work of another law professor to his book (Pacia, 2004). Ogletree issued a public apology, after which an internal investigation found he committed an honest mistake (Torres, 2004). This decision was criticized by The Harvard Crimson as imposing double standards on students and professors caught plagiarizing (The Crimson Staff, 2004).
In another case, Bindu Ganga, the director of training at Argosy University-Chicago was found to have plagiarized her doctoral research project about lying (Newbart, 2006). Ganga was fired from her job and stripped of her Doctor of Psychology degree (Newbart, 2007). This was after allegations of plagiarism from a student were confirmed by Turnitin, which showed her work was roughly 45% similar to other published works.
These unfortunate cases illustrate the importance of ensuring one’s research is plagiarism-free to avoid damage to one’s professional reputation and career.
Top 10 Free Plagiarism Checkers
Quetext is a plagiarism checker and citation assistant. It has a free Instant Search feature that helps you review your work with lightning speed. Their patented DeepSearch technology provides you with contextual analysis, fuzzy matching, and conditional scoring (Quetext, n.d.). With this, Quetext was able to correctly detect 100% of content copied and pasted from an academic journal.
Quetext has a free plan that allows you to get five free plagiarism checks every month. First-time users can get 500 words analyzed for free. More searches require you to register for free.
The free plan includes a decent amount of features for helping you steer clear of improperly attributing your sources. Contextual analysis does not only look at how closely the words match between different sources, but also considers the context of the phrases. It likewise detects synonyms in rewritten phrases through fuzzy matching. Meanwhile, conditional scoring gives weight to each match found in your work in addition to its total DeepSearch score. Once the software is done analyzing your work, its patented ColorGrade feedback gives you a visual guide for which parts of your work need to be corrected. Even with the free version, you get a citation assistant where you can manually input the details of your source material. As such, Quetext is one of the best free plagiarism checker tools you can use for your research.
Plagiarisma brands itself as an alternative to other similar, popular services like Copyscape and Turnitin (Plagiarisma, n.d.). Prior to its widespread use, scholars (see, for instance, Collberg & Kobourov, 2005) had suggested the use of a 1:1 comparison approach for plagiarism checking, Plagiarisma had since utilized in its program.
The basic tool helps you check your work against duplicate sentences online. Though the site looks dated, a simple test of copy and pasting exact content from an academic journal accurately yielded a 0% unique result. This makes it one of the best plagiarism checkers online that also happens to be free.
The webpage is straightforward to use. Simply paste the text you want to check in the text box and click the Check for Duplicate Button. Instead of using the text box, you can also upload a file to the site. You can check your work against a specific URL. File types supported include TXT, HTML, RTF, and more. The online tool supports searches for over 190 languages. It’s also possible to search for content using Google Scholar and Google Books.
However, the free version of the plagiarism checker tool supports search results for Bing only. Access to Google search results is reserved for registered users only. You can sign up as a registered user for free to get more features like faster results and fuzzy logic search.
3. Search Engine Reports
A free plagiarism checker that both content writers and researchers can use is Search Engine Reports. The online search analyzer has a rather generous limit of 2,000 words for running its plagiarism check. You can upload a file from your computer or from Dropbox. In addition, its URL exclusion feature is not only free but is capable of running up to five URLs at the same time. It’s also available in 17 languages.
It also offers three different ways to view your plagiarism search results: sentence-wise results, matched sources, or document view (Search Engine Reports, n.d.). The interface and ranking system looks very similar to that of Small SEO Tools but is more accurate. Once the plagiarism check is done, you can view the report from another webpage and share it. You can also download it as a PDF file. If it detects plagiarized content, it will give you a link to similar content. There will also be an option for you to rewrite the plagiarized content through their paraphrasing tool. Though not as accurate as Quetext or Plagiarisma, its user-friendly, visual presentation of its plagiarism check is helpful in addressing problematic parts of one’s work.
Plagium is an easy-to-use tool that allows you to detect plagiarized content in text and URLs. It does this by dividing the text into snippets and comparing them to online sources. Plagium claims that this method gives users cleaner, less noisy search results compared to other search engines (Plagium, n.d.). Moreover, Plagium correctly identified the source URL of a sample plagiarized text.
As is standard with free online plagiarism checkers, the Plagium website features a text box where you can put in text for analyzing. You can put a maximum of 1,000 characters in the text box. It gives you options to do a Quick Search or a Deep Search, but only the Quick Search option can be used without creating an account. Quick Search shows you links to matched documents the software found online. However, it does not give you a percentage of how much content was plagiarized.
Plagium also has plans which bill you for every page you search. An alternative to these is their free Google Docs add-on which has no limits on how much text you can select. It is convenient in that it highlights parts of the document where the software has detected duplicate content online. It also provides you with the links to the online source. However, its shortcoming is that it does not give you a side-by-side comparison of your work and the matched result. Still, the accuracy of its plagiarism search results makes it one of the best free plagiarism checkers available online.
5. Small SEO Tools
A plagiarism checker is one out of a hundred tools that you can find for free in the Small SEO Tools site. The tool caters mostly to the needs of content writers and freelancers who want to make sure their work is plagiarism-free for better SEO ranking. However, it can be used for research, too.
Small SEO Tools’ plagiarism checker allows you to paste text onto the text box or upload a document in various file formats. These include .tex, .txt, .doc, and more. Uploading a document from Google Drive or Dropbox is also possible. With the free tool, you can scan up to 1,000 words per search. Like most free services, you can put in a webpage URL to run a plagiarism check. You can also exclude a specific URL from your search, a feature that you would have to pay for with other providers.
Other useful features include percentage gauges, which give you objective data about how much plagiarized content is present. Its list-based, sentence-wise results show you unique versus plagiarized sentences in an easy-to-follow color-coded format. You can view a side-by-side comparison with your work versus matched results with the Document View feature. It even has a built-in automatic rewriting feature which allows you to change the wording of plagiarized content with just one click. They also have a mobile Plagiarism Checker app for iOS and Android (Small SEO Tools, n.d.). Though it is feature-rich, it only detected a small fraction of plagiarized content.
6. Pre Post SEO
Pre Post SEO hosts over 95 free tools on their site, one of which is a plagiarism checker. The tool uses a deep search algorithm to provide you with an instant plagiarism scan for your work.
Pre Post SEO features a basic tool that allows you to upload a file or copy-paste onto a text box for analysis. It recognizes .doc, .docx, .pdf, and .txt files and supports other languages. You can also choose to exclude a specific URL from your search results.
First-time visitors of the site can get 500 words scanned on the tool. For longer articles, you can register for a free account to get 1,000 words checked for free, with a maximum of 200 queries (Pre Post SEO, n.d.).
Since it’s a free plan, the plagiarism results page is as bare-bones as it can get. It gives you a dashboard with percentages of plagiarized content, unique content, exact phrase match, and paraphrase match. It underlines the text with plagiarized content and provides you with a link to check the source of the duplicate content. A copy of the plagiarism report can be viewed as an HTML file or a PDF file (Pre Post SEO, n.d.). However, the free version only picked up 5% out of sample text from an academic journal copied word for word. The premium version promises more accurate, faster results.
Duplichecker is an easy-to-use online plagiarism checker for detecting duplicate content online. It is specially designed for students who want to ensure the integrity of their academic work.
Duplichecker is a bare-bones tool that features a typical text box that lets you analyze 1,000 words of text per search. You can also upload a file or paste in a URL to check plagiarism for a specific site.
Once you click the Check Plagiarism button, it takes you to a results page. It shows you a donut chart of plagiarized vs. unique content and content with related meaning. It will also highlight the text in your work where it found similar content, and you can click on the link to check it from the site. You can also download the results as a PDF file. In the same copy-paste text done with other free plagiarism checkers on this list, Duplichecker detected only 5% of plagiarized content.
Edubirdie not only checks your work for potentially plagiarized sources but also helps you properly cite them. The site has a text box where you can paste your essay, website content, resume, or other types of papers. You can also upload .pdf, .doc, .docx, .txt, .rtf, or .odt files.
The website is free to use however, you need to create a free account in order to view the results. After checking your work, the tool gives your work a score of A to F. It will also show you a letter grade and percentage for your work’s originality, grammar, readability, synonym use, and redundancy. For the originality criteria, the tool gives you a similarity index, which tells you how closely worded your text is to a given source. It lets you view the source through a link or exclude it to improve your score.
One particularly useful feature for researchers is its ability to generate sources using APA, MLA, Chicago, and other citation styles. You can also manually cite a source but even this is a misnomer as it is a semi-automated process. Simply put in the title of the source and its URL, then choose from dropdowns for date, contributors, source type, and date accessed. It will then generate a citation that you can copy to your text or download as a .doc file. Though the free version did not correctly pick up plagiarized content, researchers will find its citation tools handy.
PaperRater is a free online proofreading service that lets authors from any level run an automated quality check on their work. PaperRater does grammar checks, offers writing suggestions, as well as runs a free plagiarism check (PaperRater, n.d.). It uses a Linux‑based operating system to check documents for similar contents (Lahiry & Sinha, 2019).
Like most free plagiarism checkers, the PaperRater site features a text box where you can paste the text you want to analyze. But what makes it unique is the customizable settings for your analysis. You can choose the education level, plagiarism detection speed, and the type of paper you are submitting from the dropdown options. Using its proprietary algorithm named Grendel, it then checks your work against over 10 billion documents to give you an originality score.
Paperrater’s free plan lets you run up to 10 plagiarism checks per month. However, the free plagiarism check does not tell you which parts of your text or document the software considered as unoriginal. It also did not return matches for completely plagiarized content. To unlock more features, you will have to get a paid Premium plan.
Plagramme is a free plagiarism checker that compares your work against a database of 80 million articles, including popular publishers like Ebsco, Springer, Oxford University Press, and more. The software also claims that its real-time check detects similar wording with papers that just went live 10 minutes or less prior to the scan (Plagramme, n.d.).
As with freemium services, you are required to create an account to use the free plagiarism checker. However, unlike most free tools, you can’t paste your text into a textbox. The only option for getting started is to upload a document from your computer. The free tool only supports .doc and .docx formats that are less than 50 MB. Also, you’re limited to low priority search, as getting the results quicker means paying extra. Once it runs a search, it will give you results in percentages for plagiarism matches, paraphrasing, and improper citations. It also gives you a rating for concentration, which represents the risk that a paper is plagiarized. In real-world testing of a plagiarized document, Plagramme did not pick up any matches at all. However, the paid versions claim to do a deep search for a nominal fee.
What’s the Best Free Plagiarism Checker to Use?
Based on the simple copy-and-paste test we employed, the best free plagiarism checker to use is Quetext and Plagiarisma. Out of all the tools in the list, these were the only ones that correctly detected that the content was 100% plagiarized. Close runner-ups were Search Engine Reports, which reported the lifted copy at 62% plagiarized and Plagium which did not give a percentage but correctly gave the link to the plagiarized content.
On the other hand, Small SEO Tools, Pre Post SEO, and Duplichecker only picked up 5% of the plagiarized content. However, the extra features and mobile version of Small SEO Tools gave it a slight edge among the other two. Meanwhile, Edubirdie, PaperRater, and Plagramme picked up 0% of the plagiarized content. Still, Edubirdie does deserve recognition for its free citation generation feature, which is helpful in avoiding non-attribution.
Ensuring your research acknowledges others’ work correctly is meticulous work. Even so, checking your paper for plagiarism is a must not only to ensure the quality of your research but also to protect your reputation. With free plagiarism checker tools, the process is much easier for students and research professionals alike.
- Collberg, C., & Kobourov, S. (2005). Self-plagiarism in computer science. Communications of the ACM, 48 (4), 88-94. https://doi.org/10.1145/1053291.1053293
- Enders, Walter & Hoover, Gary. (2004). Whose line is it? Plagiarism in economics. Journal of Economic Literature, 42, 487-493. https://doi.org/10.1257/0022051041409066
- Karabag, S.F., & Berggren, C. (2012). Retraction, dishonesty and plagiarism: analysis of a crucial issue for academic publishing, and the inadequate responses from leading journals in economics and management disciplines. Journal of Applied Economics and Business Research, 2, 172-183. https://ssrn.com/abstract=2190694
Lahiry, S., & Sinha, R. (2019). Creativity is intelligence having fun, originality an undetected plagiarism! Indian Journal of Dermatology, Venereology & Leprology, 85 (4), 436-438. https://doi.org/10.4103/ijdvl.IJDVL_71_18
- MacLennan, H. (2018). Student perceptions of plagiarism avoidance competencies: An action research case study. Journal of the Scholarship of Teaching and Learning, 18 (1), 58-74. https://doi.org/10.14434/josotl.v18i1.22350
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- Pacia, R. (2004, September 14). Harvard Law prof admits to plagiarism. Yale Daily News.
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- Roig, M. (2011). Avoiding Plagiarism, Self-plagiarism, and Other Questionable Writing Practices: A Guide to Ethical Writing. Tuscaloosa, AL: Department of Biological Sciences, College of Arts & Sciences, The University of Alabama.
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- The Crimson Staff (2004, September 13). What academia is hiding. The Harvard Crimson.
- Torres, H. (2004, September 25.). Ogletree admits to plagiarism. The Harvard Law Record.