Tools for Teachers

Top 12 Online Plagiarism Checkers for Teachers and Educators

Online Plagiarism Checkers for Teachers

The Internet gave students the opportunity to get useful information anytime and anywhere, but also to steal it. Today more and more teachers rely on online plagiarism checkers in order to make sure they get original works. However all these tools differ in quality of examination, available options, and price.

The free solutions are not suitable for constant use, as they’re usually worse at detecting plagiarism and have a number of limitations. The paid solutions seem to be all equally perfect, but in fact, examination shows that for the same price you can get vastly different results. For this article, I’ve tested the best online plagiarism checkers and hope you will find this comparison useful.

The table below lets you overview the capabilities and price of the best checkers at a glance. The quality rate in the third column is based on a practical test, in which each tool scanned three different documents: plagiarized text, text after character replacement, and unique original text. While some of the plagiarism detectors successfully passed the test, recognizing cheating and accurately tracing the original sources, others were not so precise.

You can learn more details about each checker, their unique features and pricing policies in the overview below the table.

Comparative chart
Acceptable formats Features Quality of examination/Price
1. Plagramme
  • DOC and DOCX for free version users
  • HTML, PDF, RTF, TXT, EBOOK and other formats are available for licensed users through customization.
  • Plagiarism percentage
  • Multiple language support
  • Character replacement detection
  • Downloadable report
  • Integration via API and Moodle LMS Plugin
  • Bad citation and paraphrase detection
  • Online correction tool
5/5

  • The basic verification is free.
  • The cost for additional features starts from $0.35 per page.
2. PlagScan
DOC, DOCX, PDF, TXT, ODT, RTF, PPT, ZIP, URL, and others
  • Plagiarism percentage
  • Customizable and downloadable report
  • API integration
  • Citation, reference and URL exclusion
  • Doc vs doc comparison
  • Multiple document check
  • Email notifications
  • Web import (e.g., from Dropbox)
4/5

  • Private users buy scanning packages: $6 for 5,000 words, $13 for 20,000 words, $25 for 50,000 words, $50 for 125,000 words.
  • Organization can acquire subscription plans at $19.99/month or more.
3. PaperRater
DOC, DOCX, TXT, ODT, RTF are available for users with a premium membership
  • Plagiarism percentage
  • Automatic grammar, spelling and punctuation proofreader
  • Writing suggestions
  • Automatic paper grading
2/5

  • Basic verification is free.
  • Premium plans: $14.95/month, $7.95/month if paid annually.
4. Noplag
DOC, DOCX, RTF, TXT, ODT, HTML, PDF
  • Plagiarism percentage
  • Customizable and downloadable report
  • Citation and reference exclusion
  • Doc vs doc comparison
4/5

  • Free when checking against a custom library.
  • The cost for using ready databases starts from $0.04 per page.
5. Copyscape
Users of the free versions can submit a URL (of HTML pages only).

Premium account owners can also paste in text.

  • API Integration
  • Doc vs doc comparison
  • Batch Search for checking an entire website
2/5

  • Basic verification is free.
  • The cost for Copyscape Premium starts from $0.05 per verification with a minimum purchase of 100 credits ($5).
6. Unplag
DOC, DOCX, RTF, TXT, ODT, HTML, PDF, ZIP
  • Plagiarism percentage
  • Multiple language support
  • Character replacement detection
  • Downloadable report
  • Integration via API, LTI and Moodle LMS Plugin
  • Doc vs doc comparison
  • Multiple document check
5/5

  • $9.97/month,
  • $20.95/three months,
  • $59.88/year for individual clients
7. Plagiarism Software
DOC, TXT and URL
  • Plagiarism percentage
  • Downloadable report
  • URL exclusion
  • Keyword detection
 4/5

  • First three trial checks are free.
  • Premium plans:
  • $10/month, $20/month, $30/month.
8. PlagTracker
Copy & Paste option for the free version. The Premium account owners can also upload files in DOC, DOCX and TXT.
  • Plagiarism percentage
  • Automated grammar proofreader
  • Multiple language support
  • Reference exclusion
  • Downloadable report
  • API Integration
2/5

  • Basic verification is free.
  • Premium plans: $7.95/month, $95.40/year.
9. Quetext
The Copy & Paste option only.
  • Multiple language support
 1/5

Free

10. Plagiarisma
TXT, HTML, RTF, DOC, DOCX, XLS, XLSX, PDF, ODT, EPUB, FB2, PDB, and URL
  • Plagiarism percentage
  • Multiple language support
  • Downloadable report
  • Automatic article rewriter
  • Spell checker
3/5

  • The basic verification is free. Premium plans: $5/day, $25/month, $30/three months, $50/six months.
11. Grammarly
DOC, DOCX, ODT, TXT, and RTF
  • Plagiarism percentage
  • Downloadable report
  • Automatic grammar, spelling and punctuation proofreader
  • Synonym suggestions
3/5

  • $29.95/month,
  • $59.95/three months,
  • $139.95/year.
12. Turnitin
DOC, DOCX, TXT, PDF, RTF, PS, WPD, HTML, HTM
  • Plagiarism percentage
  • Customizable and downloadable report
  • Citation and reference exclusion
  • Doc vs doc comparison
  • Feedback option
  • Couldn’t test out
  • Pricing should be discussed directly with the Turnitin sales managers.

1. Plagramme

Saved reports in the Plagramme dashboard

Plagramme is the brainchild of the idea to create a plagiarism checker that would be perfect with all languages, not just English. As a result, Plagramme is the best in small language detection and as good as the oldest and best known competitors. The service offers some exceptional scoring and highlighting options based on an advanced plagiarism detection algorithm. This allows users to be sure they will be alerted about any plagiarism risk.

Text length limits

Plagramme has a minimum text length: the shortest document should contain at least 250 words.

The standard limit of 50 MB per document can be changed by customization. Both huge and small documents are checked with the same accuracy.

Examination

For examination, Plagramme uses their own database, as well as that of their partner. Overall, the continuously growing database now amounts to 14 trillion websites with more than 300 GB of materials.

Plagramme features an enhanced scoring system, whose capabilities go beyond simple detection of plagiarism percentage. For example, if a student’s paper contains one fully copied and 99 unique pages, then a standard similarity score would just amount to 1%. At the same time, Plagramme is able to refer such papers to the “Highest plagiarism risk” group, thus indicating that the document needs a deeper look.

It’s also worth mentioning that Plagramme defines plagiarism as similarities of big texts and therefore doesn’t mark simple words. This allows you to avoid a false positive for plagiarism, when in fact the paper is unique.

Highlighted plagiarized text and sources in a Plagramme report

Support

Support is available inside the service and by email. The response time is from 2 minutes to 3 hours. In my independent testing, Plagramme demonstrated the promptest and at the same time qualified support service.

Pricing

Plagramme doesn’t charge for verification. Users are only asked to pay for detailed plagiarism reports and additional features. The price depends on the document size and the plagiarism percentage and starts from $0.35. Plagramme grants free accounts for educators and discounted accounts for researchers.

2. PlagScan

The PlagScan interface

PlagScan leverages a unique two-step algorithm based on the latest research in computer linguistics. It boasts a number of robust features, which allow users to check several documents simultaneously, exclude some matching text from the report, compare documents to each other, get results by email, and more.

Text length limits

Users can scan documents of up to 1,000 words and less than 300 kB at a time with the trial version.

Examination

Since comparing documents to all the other documents in the world is unpractical, PlagScan has developed an algorithm that searches for thematically related documents. In other words, the document’s subject determines the sources it’s compared to. The search is based on the Web and the PlagScan database. It’s also possible to create a custom library of documents, and check new text against it.

PlagScan considers three consecutive words matching as plagiarism, making even a rewritten text with a different word order or synonyms prone to be detected as plagiarism. Upon verification, PlagScan generates a customizable report that can be viewed and edited in a browser and also downloaded. The MS Word version of the report contains interactive annotations for plagiarized phrases (this option is available for files with less than 100,000 words or 10 MB).

Highlighted plagiarized text in a PlagScan report

Support

You can send a message to the support team using the contact form on the website.

Pricing

PlagScan has different pricing policies for individuals and organizations. Private users don’t buy a subscription, but pay for credits: $5.99 for 5,000 words, $12.99 for 20,000 words, $24.99 for 50,000 words, and $49.99 for 125,000 words.

Organizations can acquire subscription plans at $19.99/month or more (paid annually), depending on the number of users and other factors.

PlagScan offers a free trial, allowing new users to check up to 2,000 words for free upon registration and email confirmation.

3. PaperRater

The Paperrater interface

Paperrater is another proofreading solution that combines grammar and plagiarism checking. Based on an Artificial Intelligence engine, it automatically analyzes and scores your text, and provides relevant feedback. Paperrater is a web-based service, which means that it doesn’t require any software to be downloaded and installed.

Text length limits

Paperrater has a 15,600 character limit (more than 5 pages at 400 words/page) for a free account and a  72,000 character limit (more than 20 pages at 400 words/page) for a premium account.

Examination

Instead of maintaining an internal database, Paperrater compares submitted text to over 10 billion documents on the Web. The plagiarism detection doesn’t rely on past submissions: most papers are deleted from the website within hours after being uploaded.

Upon verification, Paperrater generates a simple report showing the originality percentage and the list of matching web pages for the whole text and for particular phrases.

A list of sources in a Paperrater plagiarism report

Support

Responses are almost always given within one business day and usually within a few hours.

Pricing

Paperrater offers a basic subscription for free, which comprises standard plagiarism verification. The premium memberships costs $14.95/month or $7.95/month (if paid $95.40 for a year) and includes improved plagiarism detection. For example, the free plagiarism check doesn’t identify any unoriginal parts, while the premium service shows unoriginal text that matches an Internet source. The premium account is granted for free for schools.

4. Noplag

Noplag's four search options

Noplag is an online plagiarism detection service with a modern interface and a wide range of flexible options, such as citations & reference detection, simultaneous verification of multiple documents, report customization, and more. Apart from checking against the Web and its database, Noplag allows you to create a custom library of your own content, and check new documents against it for free.

Text length limits

Users cannot upload files with more than 100,000 characters for one check.

Examination

Noplag checks documents against the Web, as well as its own database that contains more than 5 million academic papers, journals, publications, articles, and more. Users can also upload their own files and check new documents against them for free.

Every verification generates a report with the list of matches, as well as highlighted plagiarized parts of the text. The reports can be instantly downloaded, shared or commented on. Users can omit correct citations and references from the results, which is especially convenient for checking academic papers.

Highlighted plagiarized text and sources in a Noplag report

Support

Noplag provides email, phone and chat support.

Pricing

The price depends on the type of examination. You can choose to check your document against the Web ($0.1 per page), the Noplag Database ($0.04 per page), a publication ($0.05 per page), your personal library (free), or use all these options altogether. One page is considered to consist of roughly 200 words.

5. Copyscape

The Copyscape interface

 

Copyscape is made to protect content from being copied and stolen. It achieves this aim through a range of free and paid solutions, including Plagiarism Checker, Copysentry (which automatically monitors the web for copies of your content), Comparison Tool (which compares two articles or web pages), and others.

Text length limits

Copyscape doesn’t place any limits on the text length, though it’s recommended to check under 2,000 words at a time. The free version provides a limited number of scans for a certain website per month.

Examination

In order to identify online matches, Copyscape doesn’t use its own database instead it relies on various search indexes. Simple reports don’t contain information on the plagiarism percentage, but display a list of the internet sources where matching phrases have been detected. Plus, Copyscape highlights identical text on the corresponding web pages, not within the verified document.

Highlighted plagiarized text on the matching web page

Support

All support is taken care of via email. The response time is from a few hours to 48 hours.

Pricing

Copyscape Premium requires search credits to be purchased. One search credit equals one web page or portion of text checked, and costs $0.05 with a minimum purchase of 100 credits ($5).

Copyscape has a free version that allows you to submit URLs for pages in HTML. With Copyscape Premium, you can paste in text along with URLs, scan an entire website, filter results, check for duplication within users’ own content, and more.

6. Unplag

The Unplag interface

Unplag scans one or multiple documents against a real-time web index or other users’ documents or folders.  If you’re an educator, you can use Unplag’s additional options, such as creating multiple student accounts, providing access to shared files and viewing students’ check history.

Text length limits

With Unplag, you can check up to 500 words at a time with the free trial version, and up to 100,000 words or a 70 MB document with the paid individual/corporate account.

Examination

Unplag uses a live web index, which means that it detects matching even within sources that have just been indexed by search engines. Additionally, it scans gold and green open access repositories and journals. Users can also choose a Doc vs Doc check to compare the originality of one to one or several documents/folders against each other.

The verification report has a number of customization options. It’s possible to omit correct citations or web pages, for example those that have less than 5% of matching text with the verified document.

Highlighted plagiarized text and sources in an Unplag report

Support

Support is provided via email, phone and chat from Monday to Friday.

Pricing

Individual users can acquire a subscription for $9.97/month, $20.95/three months or $59.88/year. Corporate clients need to contact Unplag’s sales manager to discuss the price individually.

7. Plagiarism Software

The Plagiarism Software interface

Plagiarism Software is an online similarity detection engine that scans text documents and web pages. It has three different subscription plans, and allows users to check the first three documents for free.

Text length limits

1,000/ 2,000/ 3,000 words per search depending on the subscription model.

Examination

Plagiarism Software compares submitted text to billions of indexed web pages, and creates a report with a general list of plagiarized sources, as well as a list of sources for each matching phrase. It also shows keyword density, which can be useful for copywriters and SEO specialists. Before verification, users can indicate a URL that they want to exclude from the results.

The list of sources in a Plagiarism Software report

Support

Support is available via email, Skype and WhatsApp.

Pricing

The three subscription models cost $10, $20 and $50 per month respectively, and only differ in the number of total searchers and words per search. You can perform three checks for free before subscribing.

8. PlagTracker

The PlagTracker interface

PlagTracker is an online plagiarism checking service built by two Computer Science students who developed a unique algorithm for plagiarism detection. It’s available in free and paid versions that differ in speed of checking and other options.

Text length limits

With PlagTracker, you can submit up a text with up to 5,000 words in the free version and texts of any length with the premium version.

Examination

PlagTracker checks documents against 14 billion web pages and 5 million academic papers from the database. The report shows the general plagiarism percentage and number of matched sources. By clicking on the highlighted plagiarized parts of the text, you will see links to the corresponding sources. PlagTracker saves reports for one week and allows users to delete them manually at any time.

Highlighted plagiarized text and sources in a PlagTracker report

Support

You can leave questions and suggestions by filling out the contact form on the website. Didn’t get a reply to my questions when writing this article.

Pricing

The Premium account costs $14.99/month or $7.49 if paid $95.40 per year.

The free version immediately checks the first document, then puts consecutive texts in the queue and promises to email the report within 30 minutes (didn’t receive emails when testing though). New documents can be submitted after the report has been generated.

The Premium version allows users to get reports instantly, check documents for grammar, exclude references from the verification, download PDF reports, and upload unlimited (both in number and size) documents instead of pasting them in. It also offers an access to an API so that PlagTracker can be integrated with other applications.

9. Quetext

The Quetext interface

Quetext is a simple plagiarism detection engine based on Natural Language Processing and Machine learning algorithms. Raising money on advertising, Quetext is free for users and doesn’t require registration.

Text length limits

Users can paste in text with less than 20,000 words.

Examination

Quetext scans documents for plagiarism against web sources. It doesn’t consider common phrases as cheating in order to prevent a false plagiarism detection. Quetext uses a patented machine-learning algorithm and doesn’t simply find exact matchings, but checks if they can actually be considered as plagiarism.

Upon verification, Quetext generates a simple report that doesn’t show originality percentage, but highlights the matching parts of the text and provides users with the sources list.

Highlighted plagiarized text in a Quetext report

Support

You can leave general inquires or feedback via email. Didn’t get a reply for my questions when writing this article.

Pricing

Quetext offers a free version only.

10. Plagiarisma

The Plagiarisma interface

Plagiarisma can be used as an online service, desktop tool on Windows, or a mobile app for Android or BlackBerry. This tool doesn’t work with English texts only: overall, it supports more than 190 languages. Plagiarisma’s additional features include Article Rewriter, which generates unique text by changing synonyms, and Similarity Checker, which compares two documents against one another.

Text length limits

Plagiarisma checks up to 2,000 characters per search.

Examination

To detect plagiarism, the engine compares submitted documents against the Web. It’s also possible to perform a check using Google Scholar or Google Books in order to detect plagiarism in term papers, books, essays, and journals.

Plagiarisma breaks the text into phrases and provides a list of matching phrases and corresponding sources. The plagiarized parts are also highlighted within the text, but cannot be clicked. Users of both the free and premium account can open and download the report in PDF.

The list of sources in a Plagiarisma report

Support

To get help from technical support, you need to fill out the contact form on the Plagiarisma website. Note that Plagiarisma can ignore your email in case you aren’t a premium member and don’t indicate a valid order ID. Didn’t get a reply for my questions when writing this article.

Pricing

The free version allows to scan up to three documents per day.

The subscription plans offer the following prices: $5/day, $25/month, $30/three months, and $50/six months. The daily plan allows you to perform up to 100 searches, while others are unlimited. The monthly plan grants shared access for up to 25 users who can work with the service simultaneously.

11. Grammarly

Saved report in the Grammarly dashboard

Grammarly is more than a plagiarism checker. Built as an automated proofreader, it also helps writers find and correct grammar, spelling and punctuation mistakes, and enhances vocabulary usage. Grammarly can be used as a desktop application, an add-in for Microsoft Office, or a browser extension for Chrome and Safari.

Text length limits

You can upload a document of less than 40 MB in size. If you’re using an online editor, you can check up to 60 pages at a time.

Examination

Grammarly checks documents against more than 8 billion web pages that have been indexed by the major search engines. It scans Internet sources in HTML, PDF, DOC, DOCX, and TXT formats. The plagiarism checker is just one of the options of the Grammarly editor, and it needs to be enabled manually for every document search (which is quite easy to do).

Grammarly cites one source for every matching phrase. It also counts the number of unoriginal words in a passage and shows how to use citations correctly in order to avoid accidental plagiarism.

Highlighted plagiarized text and sources in a Grammarly report

Support

You either email your questions directly or fill out the request form on the website. A response can be expected within 24 hours.

Pricing

Grammarly offers a free version that covers a basic grammar and spelling editor, but doesn’t allow you to scan for plagiarism.

There are three paid subscription plans: $29.95/month, $19.98/month (if paid $59.95 per three months), and $11.66/month (if paid $139.95 per year). The Premium account features an advanced editor and plagiarism detector, and can be used on up to five different computers.

12. Turnitin

Turnitin is a comprehensive solution that allows educators to perform plagiarism checks, leave feedback on specific phrases or entire assignments, and grade submitted works. Students can log in to their Turnitin account to see revealed matches and instructor feedback.

Text length limits

The maximum length for each submitted document is 400 pages.

Examination

With Turnitin, instructors can check academic works themselves, or ask students to submit works through their personal accounts. If necessary, students can amend their works, however rewritten documents can be resubmitted only 24 hours later, which is meant to prevent students from cheating.

By default, generated plagiarism reports are available for instructors only, but at their discretion, students can also view reports. Additionally, instructors can exclude citations and references, as well as  “small matches” in order to prevent the detection of common phrases.

Turnitin provides you with three main search options: examination against Internet resources (including archived Internet data), against a repository of previously submitted works, and against a repository of journals, periodicals, and publications. You are free to check documents against any specific repository, or all of them.

Upon verification, Turnitin highlights identical or similar text with different colors that correspond to different matching sources. Each source has a matching percentage.

Highlighted plagiarized text and sources in a Turnitin report

Support

Turnitin offers free webinars for orientation and training. You can also contact the support specialists via phone or the form on the Turnitin website.

Pricing

Pricing should be discussed directly with the Turnitin sales managers. No free trial is available.

Conclusion

A plagiarism checker is a relatively simple tool, but it has the big responsibility of detecting cheating in academic works, website content, and other types of text. To choose the right software, it’s crucial to test its real capabilities beforehand. According to my independent examination, the two best checkers are Plagramme and Unplag, as they were accurate in detecting plagiarism and its sources in the test documents. If you need additional features apart from plagiarism detection, then Grammarly and PlagScan are a good choice.

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