Best Plagiarism Checker:
Top 10 for Students and Teachers

Tested on academic texts
Audited via mystery shopping
Verified by A*Help experts
🔥 published August 16, 2022 - updated September 25, 2023

Having a quality plagiarism checker at your disposal has never been more crucial. The academic field is shifting towards progressive changes, introducing new ways for students to modify and facilitate their studying. While the tip of the iceberg seems exciting, what is hidden beneath such rapid advancements is unknown. With this regard, students and educators need more powerful software that can protect the originality of the paper, the integrity code and prevent unintentional copying.  

Plagiarism checkers promise to scan text and documents, detect duplicate content or improper citations, verify sentence similarities, and much more. Many plagiarism checkers claim to distinguish AI-generated text and paraphrasing, which are common in the rise of ChatGPT and other AI-powered writers. The Academic Help team decided to test the best anti-plagiarism solutions that could bring value to learners. Our experts compiled a list of services that guarantee to show the best and most accurate results. For a more detailed list of criteria, you can take a look at our buying guide. Traditionally, we provide an unbiased ranking of plagiarism checkers, which is based on real experiences and interactions with these services, as well as the A*Help scoring system. See How We Test Plagiarism Checkers for more details about our testing approach.

TOP services Our verdict A*Help Score 🔥 Updated July 2023
Service icon
AHelp Plagcheck
Best plagiarism detector 86.5/100 Get free access
Service icon
Best experience 86/100 Visit website
Service icon
Best features 85.1/100 Visit website
Service icon
Originality AI
Best free trial value 79.1/100 Visit website
Service icon
Best price 78.6/100 Visit website

Our approach for selecting the best plagiarism checker for students

The Academic Help team sets out a goal to find a plagiarism detector that can cater to learners’ needs. To make the search more efficient, our experts conduct real mystery shopping. This experiment is bound to mimic the path of a student who would need to use any plagiarism checker to scan their papers. During this experiment, we checked written pieces to analyze the essential criteria, such as value for money, overall experience, and check quality.

Unquestionably, the main focus of our assessment is directed to check the quality of every document. Our experts prepared 5 different essays on the topic “Characteristics of a Leader” to be run through every service.

This is what we tested:

  • A fully human-written text 
  • A sample from the Internet (100% taken from the Internet)
  • An AI-paraphrased text via ChatGPT (80% generated by AI)
  • An AI-paraphrased text via Quillbot (80% generated by AI)
  • An entire text with replaced characters 

We ran each of these texts through all the plagiarism checkers that we had on the list (12) and attentively assessed the quality of detection. But we did not cast away other little details like registration, user experience, available features, and, of course, free trial or paid plans. Checking everything helps our experts make the final call. 

Below in the table, you can find our assessment criteria for the check quality aspect:

> Text > Best result > Acceptable result
Human-written text 100% free of plagiarism 10% margin of error
Internet sample 100% plagiarism detected 10% margin of error
AI paraphrase (2 texts) 100% free of plagiarism 10% margin of error
Replaced characters 100% plagiarism detected Flagged character replacements

Best Online Plagiarism Checker

An infographic that shows a list of 5 best plagiarism checkers with the A*Help score assigned to each

The winner in the category for the best online plagiarism checker is Copyleaks has been helping students around the world for 8 years now. The service suits different budget preferences since it has both free and paid plans for learners. Overall, this plagchecker is easy to use, and it does not take much time to scan documents. Apart from the basic features that almost every plagiarism checker offers, this service has a list of advanced options, such as cross-language search, ai detection, text comparison, and OCR scan. Copyleaks promises to show stellar results, and it does not disappoint.

Top Plagiarism Checker Reviews

According to our Mystery Shopping Reviews (2023), we can recommend the following legit plagiarism-checking services:

A screenshot of the Copyleaks homepage from the list of best plagiarism checkers for students

value for money
overall experience
plagiarism detection
86 is a well-known plagiarism-checking service that can verify written material through AI detection. Copyleaks is an indispensable tool for anyone who works with texts and content in general. 

Our experts received the full results of the checkup of 5 texts. Copy leaks have access to more than one database and can even compare the files in the user’s current batch. This plagiarism checker scanned all our documents relatively fast and showed the final results in percentage on the screen with color-coded details, pinpointing complete or partial plagiarism, paraphrase, or word omission. Moreover, the report could be additionally found in the personal account on the platform as well as all previously checked documents. 

Students can access Copyleaks for free plagiarism and AI checkups, but with limitations of up to 10 pages and fewer services. The paid subscription for 100 pages starts at $10.99 monthly. Using this detector is easy, and it does not take long to set up a personal account. 

Copyleaks showed excellent results when detecting plagiarism in human and internet texts. Also, this plagiarism checker did not disappoint when scanning an essay with character replacements. However, despite the advanced “AI-detect” feature, Copyleaks could not identify essays that had been rewritten by ChatGPT and Quillbot. Yet, overall, the general result was great. 

Plagiarism detection: 44/50

> Text > Best result > Acceptable result > Copyleaks result
Human-written text 100% free of plagiarism 10% margin of error 92.6% free
Internet sample 100% plagiarism detected 10% margin of error 100% detected
AI paraphrase (2 texts) 100% free of plagiarism 10% margin of error 80.35% plagiarism detected
Replaced characters 100% plagiarism detected Flagged character replacements 0% detected

Copyleaks is a plagiarism detector that has a long list of basic and advanced features to offer. This service has earned the trust of many leading organizations and institutions, such as, Medium, and the University of Cambridge. Copyleaks does a good job of detecting different malfunctions with texts. 

The Good
  • Great list of free features
  • Many advanced features
  • Support on the platform
  • Free trial
The Bad
  • Impossible to detect AI-generated content
  • No browser extension

A screenshot of the Quillbot homepage from the list of best online plagiarism checkers

value for money
overall experience
plagiarism detection

Quillbot appeared in the market in 2017. This service was meant to be a writing mentor for anyone who needed to express their thoughts on paper on a daily basis. Users could install the desktop version of the tool, or add it to their Chrome extensions, or simply use it online. Currently, Quillbot offers more services beyond that. That’s why the A*Help team decided to verify if it could assist students and educators with detecting plagiarism. 

Quillbot accommodates many different features. And while students can use it for free to rewrite some sentences with the help of AI technology or polish their grammar and spelling, the plagiarism checker comes with a monthly subscription of $9.95 (20 pages available). Are you lucky to have a promo code? Quillbot accepts them too. 

Working with this plagiarism detector was smooth like butter. We signed up, paid for the subscription, and started checking our documents. The scanning process took only a few seconds, and we had results on our screen. Quillbot also did a great job at detecting human and internet texts. Moreover, the tool’s technology could mark the swapped letters in the last essay. But, detecting ai-paraphrased texts was not its strength. We specifically had two essays: one where sentences were rewritten by ChatGPT; and the second one, with Quillbot paraphrase. 

In the long run, this plagiarism detector could not see its own changes in the text.  However, it’s worth mentioning that the overall results were satisfactory.

Plagiarism detection: 46.1/50

> Text > Best result > Acceptable result > Quillbot result
Human-written text 100% free of plagiarism 10% margin of error 91.2% free 
Internet sample 100% plagiarism detected 10% margin of error 99.7% detected
AI paraphrase (2 texts) 100% free of plagiarism 10% margin of error 82.65% plagiarism detected
Replaced characters 100% plagiarism detected Flagged character replacements Marked characters in the text

Generally speaking, Quillbot is a user-friendly and easy-to-use service for students when doing their studies. It has many features that can come in handy for learners. Additionally, like many academic help platforms, it tries to introduce advanced tools. But, coming from practical experience, there is still room for improvement.

The Good
  • Affordable subscription
  • Browser extension
  • Fast detection process
The Bad
  • Lack of free checkups
  • The paid subscription allows only 20 pages per use

Service logo


A screenshot of the Originality.AI homepage from the list of best plagiarism checker websites

value for money
overall experience
plagiarism detection

Originality AI has a promising name that can attract many learners and educators. Being in the market since 2023, this service is making big strides in the direction of facilitating academic life. 

The A*Help team was pulled towards the impression that OriginalityAI only works with generated content. In practice, this service can help detect plagiarism in written pieces as well. During our mystery shopping experiment, it cost us $20 to scan our papers. However, please, note that pricing policy changes on the service. Also, you can always add 100 words for $0.01 to get scanned if the paid plan doesn’t cover your needs. Have you got a coupon? Don’t hesitate to use it to cut the fee. OriginalityAI can even keep you on the edge of your seat, money-wise. Just install its Chrome extension and get 50 credits to check 500 words for free. 

According to our plan, we dealt with the technical part and were ready to move to practice. As always, creating a personal account did not slow us down. But the scanning time per document did. The final results were available on the screen where OriginalityAI showed matching sources and phrases. Let’s speak numbers, the human-written, and Internet were accurately detected by OriginalityAI. However, the service could not differentiate the character swap in the last essay. And detecting ai-generated content in two texts was not entirely successful for this service. With such outstanding results in detecting both plagiarism and AI, this provider closes our top 3 best plagiarism checking services. 

Plagiarism detection: 41.1/50

> Text > Best result > Acceptable result > OriginalityAI result
Human-written text 100% free of plagiarism 10% margin of error 100% free
Internet sample 100% plagiarism detected 10% margin of error 92% plagiarism detected
AI paraphrase (2 texts) 100% free of plagiarism 10% margin of error 22% plagiarism detected
Replaced characters 100% plagiarism detected Flagged character replacements 0% detected

According to our Originality.AI review, it is a great tool for the modern agenda in education. It can detect both plagiarism and ai-generated text in written pieces.

The Good
  • AI detection feature
  • Browser extension
  • Affordable price
  • Free trial
The Bad
  • Takes long time to scan documents
  • Limited features

Service logo


A screenshot of the PlagiarismCheck homepage from the list of top plagiarism checkers

value for money
overall experience
plagiarism detection

Established back in 2015, PlagiarismCheck was created to protect original work and be a reliable support for educators. This tool  is ready to serve organizations and individual students. 

The A*Help team decided to check to what extent the service can provide accurate results to their users. This plagiarism checker promised us everything that we had seen so far: 100% accuracy results, AI-generated text and character swap detections. The A*Help experts created an account to start working with this service. is an affordable tool that costs $5.99 to check 20 pages. If you need to scan more pages, there are plans up to 300 pages ($45.49). 

Overall, this company designed an easy-to-use platform. In the beginning, this service provides an onboarding session for new users where it teaches them about all the functions. If you have questions, contact the support on the site. Students may need to be patient while the service processes their documents.

PlagiarismCheck showed standard results. Detecting plagiarism in human-written and Internet texts was not a problem for this service. But, it came as a surprise to us when the tool showed the percentage of ai-generated text in a fully written human essay. Moreover, this plagiarism checker could detect some amount of AI-paraphrased sentences in essays. However, the service did not find any letter replacement in the last document.

Plagiarism detection: 41.6/50

> Text > Best result > Acceptable result > PlagiarismCheck result
Human-written text 100% free of plagiarism 10% margin of error 100% free 32.70% ai detected 
Internet sample 100% plagiarism detected 10% margin of error 99.13% plagiarism detected
AI paraphrase (2 texts) 100% free of plagiarism 10% margin of error 31.83% plagiarism 
Replaced characters 100% plagiarism detected Flagged character replacements 0% plagiarism detected

In general, PlagiarismCheck can suffice general academic needs. It can scan your text and documents, as well as verify grammar in written papers. And while it does show average results in Plagiarism detection quality, still it can be used as a solid foundation. Sure, its AI detection feature is still under development but it is showing tangible results.

The Good
  • Access for organizations and individuals
  • Affordable paid plans
  • Built-in AI detector
The Bad
  • Not possible to try before registration
  • Fails to detect character replacement

A screenshot of the Quetext homepage from the list of plagiarism checkers

value for money
overall experience
plagiarism detection

Founded in 2016, Quetext’s plagiarism checker promises to solve any writing issues, help students with citations, and, most importantly, scan their writing pieces for plagiarism. 

We did not experience any trouble when working with Que text. The procedure was standard. First, we created an account, paid $10.49 for a monthly subscription to check our papers, and started running our essays through the plagiarism checker. There is a free trial on Quetext, but it is limited to checking only one page. So, if your text or a document exceeds the mentioned limit, you will instantly get transferred to the sign-up form in order to create a personal account.

The team at Quetext goes above and beyond in their efforts to enhance their product. Every user has an onboarding session where they get acquainted with the service. If you have issues or questions during the process, click “Help” button on your right, and their support team will take care of everything. 

Quetext showed excellent results when scanning human-written and Internet texts. But, detecting AI-paraphrased sentences or character swaps was difficult for this plagiarism checker. In two AI-rewritten essays, the service failed to detect any AI-generated content but managed to detect 13% of plagiarism combined. The essay with replaced letters was neither flagged nor marked as plagiarism. 

Plagiarism detection: 41.1/50

> Text > Best result > Acceptable result > Quetext result
Human-written text 100% free of plagiarism 10% margin of error 93% free
Internet sample 100% plagiarism detected 10% margin of error 98% plagiarism detected
AI paraphrase (2 texts) 100% free of plagiarism 10% margin of error 22.5% plagiarism detected
Replaced characters 100% plagiarism detected Flagged character replacements 0% plagiarism detected

Quetext is another plagiarism detector that can aid students with keeping originality of their paper protected. However, its features are not advanced yet and need to be perfected in order to serve more purpose in detecting different changes in texts.

The Good
  • Affordable paid plans
  • Onboarding before using the service
  • Spelling and Grammar check features
The Bad
  • Limited plagiarism features
  • Impossible to try before registration

A screenshot of the Plagium homepage from the list of plagiarism checkers

value for money
overall experience
plagiarism detection

Plagium has been aiding students since 2006. This plagiarism checker continues to ensure the originality of texts by detecting and identifying possible misuse of the content. Since the academic world is evolving, so is Plagium. The service introduced its AI detector as a brand-new feature to scan documents for AI-generated texts. 

There are many different paid plans on Plagium, starting with $5 for checking 62,500 characters and up to $200 for scanning 2,875,000 characters. As of recently, users can add Plagium into their Google Docs by installing an extension in the browser. 

Scanning our documents on Plagium took up to 1 minute, but as always, we received detailed reports on the screen after every check. The service does a great job of notifying users about some warnings. For instance, when checking one of our documents, we received an alert that some text was exactly identical to some sources that Plagium had found through databases. 

As for the final results, Plagium identified plagiarism in all texts except for the essay with character replacement. However, the human-written text was marked as 14.8% plagiarism since Plagium had found some similarities with Internet text. Though, when we tried to verify manually if there were similarities, we did not find any. This case showed us that in all cases, it is necessary to double-check the similarities that are shown in the report. All in all, Plagium did a good job verifying the papers.

Plagiarism detection: 39.2/50

> Text > Best result > Acceptable result > Plagium result
Human-written text 100% free of plagiarism 10% margin of error 85.2% free
Internet sample 100% plagiarism detected 10% margin of error 98.7% detected
AI paraphrase (2 texts) 100% free of plagiarism 10% margin of error 34.5% plagiarism detected
Replaced characters 100% plagiarism detected Flagged character replacements 0% detected

Plagium is indeed a tool for students. It is accessible, easy to figure out, and budget-friendly. However, the plagiarism detection quality of the essays needs to be improved.

The Good
  • Easy-to-navigate platform
  • Onboarding tutorials
  • Cheap paid plans
The Bad
  • Takes long to scan the text
  • Limited features
  • Need to verify the final results of the scanning manually

Service logo


A screenshot of the iThenticate homepage from the list of plagiarism checkers

value for money
overall experience
plagiarism detection

iThenticate is a plagiarism checking service for the corporate market form Turnitin. iThenticate saw the world in 2004 and has been helping students and educators up until now.

This plagiarism checker has a peculiar name that can signify that this service fully supports the originality of written work. Though, it’s worth mentioning that this tool is rather pricey. If you want to check your papers with iThenticate, get ready to pay $100 for submission of one single manuscript up to 25,000 words. This plan includes 5 revisions. Do you need to check more words, say 75,000? This plan will cost you $300. Organizations can request personal subscription plans for their needs. 

Now it is time to check whether price equals quality. There were no surprises regarding the human-written and Internet texts. As for the essays with ai modifications in them, iThenticate could only spot 3% plagiarism but no text alterations. And the service did a fairly good job for the latter essay with character replacements. Even though the tool did not flag it, it marked the biggest portion of it as plagiarism, meaning that something is off with this text. By and large, this tool shows good results, but there is still room for improvement for such a price.

Plagiarism detection: 46/50

> Text > Best result > Acceptable result > iThenticate result
Human-written text 100% free of plagiarism 10% margin of error 99% free
Internet sample 100% plagiarism detected 10% margin of error 97% detected
AI paraphrase (2 texts) 100% free of plagiarism 10% margin of error 20% plagiarism detected
Replaced characters 100% plagiarism detected Flagged character replacements 99% detected

iThenticate has instilled a strong meaning of keeping the originality of written work in educational institutions. And this service tries its best to do so. It could detect plagiarism in all essays that were not written by a human. But, iThenticate requires more work to be done to detect AI-generated text.

The Good
  • Average results
  • Can scan big files
The Bad
  • Pricey service
  • Limited number of services
  • No trial

A screenshot of the Turnitin homepage from the list of plagiarism checkers

value for money
overall experience
plagiarism detection

Educators and students started using Turnitin at the end of the previous century. Since then, this plagiarism checker has built a name and reputation for itself. Over 30 million students and 15 thousand institutions are currently using Turnitin. Let’s find out if this plagiarism checker can show legit results. 

As we mentioned already, it is used mostly by educational institutions. So, unless your school or university has access to it, there is no other way to use this plagiarism checker. For us, using this service was easy and intuitive. But please note that Turnitin only works with documents. So, prepare all your papers and essays in separate documents before submitting them for scanning. The biggest advantage of Turnitin is that it can utilize various online and institutional databases. 

Turnitin gave us correct verdicts for 4 of the 5 papers we checked. This plagiarism checker easily scanned human-written and Internet texts, as well as the essay with character modifications. Not only did it show the accurate amount of plagiarism, but it also flagged the essay for a “character swap” issue. However, Turnitin did not show any results in ai-generated text.

Plagiarism detection: 46/50

> Text > Best result > Acceptable result > Turnitin result
Human-written text 100% free of plagiarism 10% margin of error 100% free
Internet sample 100% plagiarism detected 10% margin of error 99% detected
AI paraphrase (2 texts) 100% free of plagiarism 10% margin of error 20% plagiarism detected
Replaced characters 100% plagiarism detected Flagged character replacements 99% detected

In general, this plagiarism checker did a great job and proved that it can easily detect different changes in the text. However, as beneficial as it is for students and educators, still certain upgrades must be introduced so that Turnitin could react to plagiarism better and more effectively.

The Good
  • No word limits
  • Wide range of databases
  • Good detection quality
The Bad
  • Limited access
  • Unable to identify AI-generated content

A screenshot of the Plagscan homepage from the list of plagiarism checkers

value for money
overall experience
plagiarism detection

Plagscan has been in the plagiarism detection game since 2009. This solution is mostly used by academic institutions. However, it is also accessible for individual use. 

The AcademicHelp team decided to check if Plagscan can check the authenticity of a text with just a couple of clicks as they preach. Unfortunately, much like other anti-plagiarism tools, Plagscan is not available for free or for trial. Their paid plans start at $5.99 for 24 pages. Have you got a full book or a thesis to check? Scan up to 400 pages with Plagscan for $49.99. 

Like many other plagiarism checkers, this service makes a comfortable experience for their users. All documents were stored in our personal account. So, if we wanted to correct existing files, we could access them fast and run through the plagiarism scanner again. However, Plagscan does not show the final report within seconds. We had to wait around one minute for each document to get checked. 
The results Plagscan gave us were average. Human-written and Internet texts were detected correctly. However, essays with AI paraphrased sentences and letter swaps did not show such good results. This tool failed to detect artificially generated text in the former one, though it marked 80.3% of the text as plagiarism. As for the essay with character replacement, we were only notified with alerts.

Plagiarism detection: 42.9/50

> Text > Best result > Acceptable result > Plagscan result
Human-written text 100% free of plagiarism 10% margin of error 100% free
Internet sample 100% plagiarism detected 10% margin of error 93.3% plagiarism detected
AI paraphrase (2 texts) 100% free of plagiarism 10% margin of error 18.65% plagiarism detected
Replaced characters 100% plagiarism detected Flagged character replacements Alerts about modifications

Plagscan is a standard plagiarism checker that comes with the most basic features. Another thing that students need to be aware of, is the fact that this service needs some time to scan each document before it gives the final report. Overall, it can satisfy students’ standard academic requirements.

The Good
  • Basic features
  • Affordable prices
The Bad
  • No free trial
  • No browser extension or desktop version

A screenshot of the Scribbr homepage from the list of plagiarism checkers

value for money
overall experience
plagiarism detection

In 2012, Scribbr was established as a proofreading and editing company. Now, this tool serves students as a plagiarism checker, citation tool, and knowledge base. With this regard, the AcademicHelp experts decided to find out how great Scribbr was at detecting plagiarism. 

Scribbr is a handy platform yet with limited features. Students should be ready for basic use cases with this service. But, the overall guides and support chat are available to assist users in case they encounter any confusion. But most importantly, Scribbr is powered by Turnitin. It does not provide any free trial, so learners are expected to pay immediately. To scan a small document, we paid $19.95. For that price we could get up to 7 499 words scanned for plagiarism.  If we were to scan a bigger piece, it would have cost us $39.95. It’s accurate to say that Scribbr’s pricing can be seen as either affordable or expensive depending on the size of the document being checked for plagiarism.

The final reports that we received from Scribbr were far from perfect. This plagiarism checker could only detect the human-written essay. The Internet essay sample was flagged as plagiarism only by quarter. As for the essay with character replacement, Scribbr detected 99% of plagiarism. Yet, it failed to spot any interferences in the texts with ai modifications. 

Plagiarism detection: 31.6/50

> Text > Best result > Acceptable result > Scribbr result
Human-written text 100% free of plagiarism 10% margin of error 100% free
Internet sample 100% plagiarism detected 10% margin of error 25% detected
AI paraphrase (2 texts) 100% free of plagiarism 10% margin of error 32% plagiarism detected
Replaced characters 100% plagiarism detected Flagged character replacements 99% plagiarism detected

So, is Scribbr legit? It is only fair to say that this service can be used among students for general purposes when proofreading and correcting the final draft of their papers. But, learners should expect mediocre results.

The Good
  • Guides and support
  • Easy-to-use website
The Bad
  • Poor plagiarism detection quality
  • Not possible to try before registration
  • Limited services

A screenshot of the Chegg homepage from the list of plagiarism checkers

value for money
overall experience
plagiarism detection

Chegg is an education company that is ready to aid students 24/7. Not only can you get professional help from tutors on Chegg, but you can also get your document checked for plagiarism.

To get started with this service, everyone needs to create an account. Please note that during the registration process, the tool asks you for information about your studies (university, what year) and others. When you’ve filled in all the necessary information, you can start working with the plagiarism checker. Chegg has a 3-day trial during which users can understand if the service meets their needs and expectations. If you are ready to proceed with Chegg, you must pay $9.95 monthly. If not, the service offers you a chance to cancel your trial. You can do it in your personal account. In case users are confused about the technicality of the tool, which is doubtful, they can find guides with instructions and advice. The rest is easy as a walk in the park. 

Regarding the results, Chegg showed an excellent score only for a human-written text. This plagiarism checker failed to flag the Internet sample and the essay with AI modifications. For the former, this platform only detected 3% of plagiarism which is rather low since the whole text was taken from the open Internet source. Essays with AI-paraphrase were only marked as a 26.5% plagiarism. However, the tool partially did a good job with an essay with character modifications. True, Chegg could not spot any letter swaps in the text. However, it counted the essay as 99% of plagiarism.

Plagiarism detection: 26.9/50

> Text > Best result > Acceptable result > Chegg result
Human-written text 100% free of plagiarism 10% margin of error 95% free
Internet sample 100% plagiarism detected 10% margin of error 3% detected
AI paraphrase (2 texts) 100% free of plagiarism 10% margin of error 26.5% plagiarism detected
Replaced characters 100% plagiarism detected Flagged character replacements 99% detected
No flags or alerts

Overall, Chegg is an affordable plagiarism checker that shows subpar results. While it proves to be an inclusive source of homework help for students, as a plagiarism checker it needs to be improved and enhanced.

The Good
  • 3-day trial
  • Affordable plans
  • Average plagiarism detection quality
The Bad
  • No support chat
  • No browser extension
  • No desktop version

Service logo


A screenshot of the Grammarly homepage from the list of plagiarism checkers

value for money
overall experience
plagiarism detection

Grammarly is a well-known service with an established brand name and reputation. You have probably heard of it or even tried it yourself to polish your writing skills, check grammar and spelling. Grammarly does a spot-on job in this niche. But can it show such great results in plagiarism checking?

The A*Help checked it, and we are ready to show you the results. Even though Grammarly is available for free, in order to use their plagiarism tool, you need to go premium. The service offers 3 different plans: annual ($12.00), quarterly ($20.00), and monthly ($30.00) subscriptions. When we paid for the plan that suited our needs, we could access the plagiarism checker in our personal account. 

Grammarly scans documents in seconds. Such speed questions the quality of the checkup. The tool only gave accurate results for the human-written text. The rest of the documents were not evaluated correctly. In short, the speed with which this service examines texts can be faulty. We witnessed it while checking the Internet sample essay. At first, the plagiarism detector found 100% of plagiarism but within split seconds, the final score was changed to 3%. Such a case points out that every document must be manually verified when using a Grammarly plagiarism checker. 

Plagiarism detection: 21.5/50

> Text > Best result > Acceptable result > Grammarly result
Human-written text 100% free of plagiarism 10% margin of error 100% free
Internet sample 100% plagiarism detected 10% margin of error 3% detected
AI paraphrase (2 texts) 100% free of plagiarism 10% margin of error 19.5% plagiarism detected
Replaced characters 100% plagiarism detected Flagged character replacements 0% plagiarism detected
No flags or alerts

The verdict follows: if you want to enhance your grammar knacks and get more accurate at writing, then definitely use Grammarly. Consider waiting to use their plagiarism checker until the Grammarly team improves their product.

The Good
  • Affordable prices
  • Sufficient number of services
  • Easy to use platform
The Bad
  • Inaccurate and poor results
  • Impossible to try before registration

Final thoughts

All modern students have to have a versatile plagiarism checking tool at their disposal. The word versatile must be underscored in this statement. The biggest uptick that everyone in academia faces is the uncensored influence of advanced technology on their studies.  

With this in mind, the A*Help team tried 12 different plagiarism detectors that proved to be well-known tools among students. Having conducted mystery shopping and fully used every service, we could specify the best ones: Copyleaks, Quillbot, and Originality.AI. True, all 12 plagiarism detectors are still undergoing changes and modifications to keep up with AI-hype However, these three at the top can serve learners and educators better in protecting the academic integrity and originality of papers.

You can find the essays that were used during our mystery shopping below: 

Human-written essay

Internet sample

AI paraphrase (2 texts)

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Buying Advice for The Best Plagiarism Checker Website

Searching for the best plagiarism checker is hard and time-consuming. But it is possible to find a service that can satisfy your academic needs. Sure, there are many plagiarism detectors online that promise stellar results. However, what is the best plagiarism checker, and what makes it such? Let’s check the main criteria to look out for when doing personal research.


One of the key yet hidden parameters that students would be interested in is features. Potentially, if you are a high-school student, a few ones would suffice. However, for more academically driven folks, the lack of features might be problematic. For convenience of the service, it would be better for the plagiarism checker to work with files, urls, and text, as well as send reports after scanning the papers. Another plus for the service would be to provide grammar and spelling checks. 

Additionally, our A*Help team recommends verifying if your chosen plagiarism checker offers advanced features, say ai-detector, cross-language search, text comparison, or even OCR scan. These may come in handy when you set out to do an extensive inspection of your academic or research paper, thesis, report, or even dissertation. 


When running a written piece through a plagiarism scanner, the results matter. To receive a more structured and precise report, it’s necessary to find a plagiarism checker with a wide range of databases. It can be the general database from the Internet. But for accuracy, it’s an advantage when the service has access to academic databases and its current batch of files with which various text formats can be compared. Moreover, it’s a win if your plagiarism detector allows you to create your personal database of your documents to save yourself from self-plagiarism. 

Free trial and Price

Both free trial and price matter. The first one is essential yet almost always not available. From the A*Help point of view, a free trial is a chance to understand if this particular service can cover all students’ needs with its services. 

Price is always a burning issue for students who are on the lookout for budget-friendly yet quality tools. When we were assessing plagiarism checkers mentioned in this article, we focused on paid plans. In general, there are three types of tariff tiers: cheap (free – $20), affordable ($20 – $60), and expensive ($60-$100). The lowest price the A*Help team paid was $5, and the highest was $100. 


Any service, platform or tool needs to be easy-to-navigate and accessible. Students value tools that are user-friendly, lag-free, and non-invasive. Another aspect is getting in touch with support. True, many plagiarism checkers are non-brainers. However, the A*Help team never discredits the fact that some learners might have issues that need to be resolved by the customer-help team. So, we paid attention to available support messengers and guides. 

Plagiarism Detection Quality

The A*Help team cares about the quality of the assignment. We had 5 different essays to check through each plagiarism checker. The final mark for all essays altogether was 50 points. The A*Help experts decided to distribute the marks the following way: 20 points for human-written text, 20 points for the Internet text, 5 points for two essays with ai-paraphrased sentences, and 5 points for an essay with character swaps. The acceptable result for the first four essays was a 10% margin of error, and for the final essay it was just an alert or a flagged mark. While the best mark was 100%. 

Such distribution helped us receive transparent scores and evaluate features in accordance with their development. Meaning, we gave ai-generated paraphrases and letter replacements a lower mark because plagiarism checkers are still learning to understand such drastic changes in texts. 

Why is a credible source of information:

Stay curious with us. has been a reliable educational resource since 2011, providing students with the latest news, assignment samples, and other valuable materials. Even with the extensive information we process, our quality remains consistent. Each team member has experience in education, allowing us to evaluate new sector offerings critically. Our reviews are up-to-date and relevant, with impartiality ensured by the A*Help score methodology from mystery shopping. We aren’t affiliated with any listed service providers. Our focus remains on providing our audience with reliable and unbiased data.


What is the most accurate plagiarism checker?

The A*Help tried many different plagiarism checkers during mystery shopping. Our experts can confirm that the most accurate services were Turnitin, iThenticate, and Quillbot. All three are not perfect for 100%. However, they were either good at detecting ai-paraphrased pieces in the text, or character modifications. Not to mention the excellent work they did with human-written and Internet texts.

What is the free best plagiarism checker?

The best plagiarism checker that has a free/trial feature is Copyleaks. During our mystery shopping, it showed the best results in the plagiarism detection criteria. However, please note that every plagiarism detection service that has free access comes with certain limitations in features. Also, there are a few more services that can technically fall under the category of free: OriginalityAI (500 words), Quetext (with limited pages), and Chegg (3-day trial).

Do plagiarism checkers actually work?

Technically speaking, yes, they do. Many plagiarism checkers you can see in the market today can scan text, url, or a document in no time or a couple of minutes. However, this is not the issue in the modern world to find a tool that works. The issue is the accuracy of the results. There are cases where manual intervention is needed to verify if a plagiarism report is showing you the right source. This particularly applies to AI-generated text and papers that have undergone further modifications.

Is 20% a good plagiarism score?

No, 20% plagiarism score is the opposite of good. While different educational institutions have different answers to this question. As well as plagiarism checkers, which have their own gradation of results. It is unanimously considered that the mark 20% is high and must be considered a great amount of plagiarism.

What plagiarism checker do colleges use?

The answer varies among schools, colleges, and universities. For instance, plagiarism checkers like Quetext and provide their service to both individuals and institutions. Whereas Turnitin works solely with educational establishments.

Does paraphrasing count as plagiarism?

Yes and no. In the first case, paraphrasing can be counted as plagiarism if the student simply takes some sentences, changes a few words, and does not mention the source. However, if the student changes the quote but cites the source, then it is not a case of plagiarism. So, always remember to include in-text citations in your written works.

Do colleges kick you out for plagiarism?

In case of severe cases of plagiarism or cheating, schools, colleges, and universities have the right to expel students. Every educational institution makes learners acquainted with the rules of academic integrity. If such rules are disobeyed, there will be punishment.

Do college professors really check for plagiarism?

Sure, but in their own individual manner. While some educators can trust only one plagiarism checker, others can be conducting their plagiarism check on various software and databases. Some professors may even double-check the written papers manually.

How many college students get caught plagiarizing?

Giving a specific answer to this question is rather difficult since different researchers during different time spans conduct surveys among students around the world. However, if we are to give a ballpark number, around 20% of students are caught plagiarizing. Nowadays, it is getting harder to say the real number since AI technology is also affecting the results of plagiarism checks. Yet, there are no studies at the current moment which can provide real numbers on that matter

How do students accidentally plagiarize?

There are a few ways how students can accidentally plagiarize their written works. The first case is when students improperly express their work on paper, not differentiating personal thoughts from quotes. And the second possible way is either the lack of in-text citations or the case of wrongly cited sources.

Do free plagiarism checkers steal your work?

No, free plagiarism checkers do not steal your work, and they are safe to use. We advise you to check short papers with the help of free plagiarism software. For instance, it may be essays, term papers, or project reports. However, if you are to scan a bigger document like a thesis or a dissertation, we’d recommend using a professional plagiarism checker.

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Comments (21)

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Ronnie Blake February 20, 2023

Plagiarism checkers are indeed important. However, they can’t replace original thought and academic honesty. So while we use these tools, let’s remember that the best ideas come from our own minds!

Chelsea Black February 19, 2023

I wish there was a more cost-effective plagiarism checker for long political science dissertations. These premium checkers can be pretty expensive for students, especially when you’re constantly submitting long papers.

Demi Sykes February 24, 2023

I feel your pain! As a PhD student, I can tell you that it doesn’t get easier on the wallet. But look at it this way, it’s an investment in your academic integrity!

Eric Davila February 15, 2023

Plagiarism checkers are truly a lifesaver for those lengthy essays we need to churn out. But does anyone else get annoyed by false positives? Nothing like getting a scare at 3am from a ‘potential’ match to a medieval manuscript in Latin.

Dawud Barnes February 22, 2023

Totally get you. Copyscape once flagged my law paper for a match with an ancient Roman law text. I was freaking out till I realized it was just a false positive.

Wendy O'Doherty February 14, 2023

As a mathematics major, I don’t have to worry too much about plagiarism in numerical answers, but these checkers come in handy for writing research papers. Turnitin has been my go-to so far.

Elsa Rios February 12, 2023

Grammarly’s been my best friend since freshman year. It not only checks plagiarism, but it also helps improve my writing. Now, if only it could write my data science papers for me…

Savanna Odonnell February 10, 2023

I can’t believe you didn’t mention the free plagiarism checkers! As a starving student, I have to rely on tools like PlagScan and PlagTracker. They might not be as sophisticated as Turnitin or Grammarly, but they’ve served me well.

Brodie Merritt February 10, 2023

Just throwing this out there…has anyone else noticed that Grammarly’s plagiarism tool can be hit-or-miss? It works fine for English papers, but it once flagged my CS assignment for plagiarizing some obscure 90s techno song lyrics!

Aminah French February 24, 2023

😂 LOL! Maybe your code was just too melodious. Couldn’t resist writing a symphony in binary, could you?

Leyla Stevenson February 5, 2023

As a history major, I constantly have to write papers and avoiding accidental plagiarism is always a concern. This list is a great resource, I’m definitely going to try out Grammarly and Turnitin. Thanks!

Priya Ballard February 18, 2023

I’d recommend using Turnitin. As a biochemistry student, I often have to check for unintentional plagiarism in my research papers. It’s a bit expensive, but it’s incredibly thorough and reliable.

TechCluster February 3, 2023

I don’t trust any of those sites. Use the internet as a source of information, but write everything else on your own. The best work and the only that cant be plagiarized comes from your brain. Don’t try to be better than you really are.

Commandarme January 19, 2023

If you’re looking for the best free plagiarism checker, save your time. Because the best one is your professor. He’ll show you the list of websites where you’ll take info from, so don’t bother

Raspin December 30, 2022

A large library of comparisons makes Turnitin the first choice of most institutions. Everything else, all other features, is irrelevant.

SmokePlumes December 3, 2022

As I couldn’t find a plagiarism checker that was free, I copied a few sentences from my paper into Google. I reworded and cited my article if it appeared on the first page. It took me a few minutes to complete my entire paper, but my professors haven’t accused me of plagiarism.

GilFrog November 21, 2022

I don’t think grammarly’s check is decent. If you don’t want to ge caught, you’d better be off with more expencive but reliable software.

BrutalGenie October 17, 2022

In my opinion, the Grammarly tool is okay. It shows you when you use exact sequences of sentences in your text and where you took them. However, I think it can only detect big chunks of text. I may be wrong though.

CrystalRage September 26, 2022

I got a grammarly premium account and the plag check that goes with it. I tested it a couple of times, and seems to be working. I don’t know how well, though. It shows some percentage of content that there has already been published and the link to where it can be found. Looks fine to me.

KookSpook September 23, 2022

Some of these tools are terrible. And the worst thing is that you have to pay for each of them not knowing if there is some really working engine behid them.

RobbingHood September 4, 2022

I’ve always been convinced that plagiarism checkers are great tools and must be available for everyone. It’s nice there is so many, but I’d prefer having fewer of them but those that really work well


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