If you want to be taken seriously online, you have to make sure your content is high-quality and plagiarism-free. Original content also ranks better with SEO, and Google will penalize you if you copy someone else’s work.

Table of Contents:

The Best Plagiarism Checker Tools
What is a Plagiarism Checker?
Why Use a Plagiarism Checker?
Benefits of Using Plagiarism Checkers
Best Plagiarism Checker FAQS

The Best Plagiarism Checker Tools of 2021

Thankfully, there are dozens of plagiarism checker tools out there to help. Not only can you check your own work, but search for any of your stuff online that may have been plagiarized. We evaluated and compared the top options to determine which is the best plagiarism checker out there!

  1. ProWritingAid
  2. Grammarly
  3. Copyscape
  4. Unicheck
  5. Duplichecker
  6. Whitesmoke
  7. SmallSEOTools
  8. Copyleaks
  9. CheckForPlagiarism.net
  10. Quetext
  11. Plagiarism Hunt

Read on for the detailed analysis of each tool.

1. ProWritingAid

Best Plagiarism Checker for Artists and Screen Writers

ProWritingAid is another heavy hitter that aims for world-class status. As one of the best grammar and plagiarism checkers, ProWritingAid is perfect for novelists, authors, and creative writers. The tool checks manuscripts, literary works, and other forms of full-length materials. It also tests for proper punctuation, grammar, and style issues.

prowritingaid screenshot

It works right inside MS Word, which makes it very handy to use. It also integrates with Google Docs and Scrivener for easy access. ProWritingAid is compatible with Windows, Mac, and integrates with Chrome and Apple browsers. However, ProWritingAid is somewhat pricey at $10 for ten scans per month.


  • Works inside MS Word.
  • Compatible with all browsers.
  • Checks full-length manuals, manuscripts, and even novels.
  • Helpful integrations for Scrivener and Google Docs.

⛔️  CONS:

  • Pricey $10 for 10 scans/month.

2. Grammarly

The Best Plagiarism Checker Overall

In the plagiarism checker contest, Grammarly wins the race. The program uses sophisticated algorithms to check for proper grammar, punctuation, tone, and plagiarism. Grammarly also checks for conciseness, readability, and also suggests vocabulary enhancements, and genre-specific writing style tips. They have three pricing plans for the Premium service (monthly, quarterly, and annually).

grammarly screenshot

Grammarly works on the web, or you can download an app to your phone, tablet, or other devices. They also offer plug-ins for most browsers and email clients, so Grammarly is continuously checking your content, whether you are drafting a text message, emailing, writing a contract, or putting together a Word document. Grammarly basically always has your back!

When checking copy for free, you can simply paste the text into Grammarly’s plagiarism checker tool and see the results. Grammarly is in partnership with ProQuest’s academic databases and relies on them as a backbone for the plagiarism piece of their software.

Grammarly’s plagiarism checker is by far the most accurate. Writing professionals and publishers swear by Grammarly’s plagiarism checker for accuracy. Although you can scan text for free, if you want to review the full results, and get access to all the fancy tools, you will need a paid plan. Grammarly offers three-tiered levels to choose from.


  • Three pricing plans available.
  • Works on the web in any browser or using an app.
  • Easy to use.
  • Helpful for academics (uses ProQuest’s academic databases) to check for plagiarism.
  • Most accurate plagiarism checker.

⛔️  CONS:

  • Need a paid plan to get all the benefits.

3. Copyscape

Best for Bulk Plagiarism Checking

Another plagiarism checker online that you can try out for free is Copyscape. You can enter a URL and let it compare the content on that page to the rest of the web. The free version is fine if that is all you need to do, but the Premium version offers a lot more bang for your buck.

copyscape screenshot

Copyscape includes things like bulk checking, managing plagiarism cases, the ability to copy/paste text to evaluate, testing your entire website at once (up to 10,000 pages), and other tools like an API to check content on your site automatically.

They charge 3 cents per search (up to 200 words) and then another 1 cent for each additional 100 words. Copyscape may be a solid alternative to Grammarly, but if you need to check a lot of content, it could get pricey quick.


  • Built-in, side-by-side comparison tools.
  • Super easy to use.
  • Quite effective at detecting plagiarism.

⛔️  CONS:

  • Fairly expensive to use, the more words, the higher the price.
  • Sometimes inaccurate highlighting of properly cited references.

4. Unicheck

Unicheck is an excellent alternative to Copyscape and other plagiarism checkers for writers who need to ensure copy-free content. The tool is best for academics and claims to be used by more than 1,100 institutions.

There are an impressive number of college and school logos scrolling on their website. User ratings are a mixed bag. Most people rate the tool with about 4.5 stars and appreciate its accuracy, ease-of-use, and vast database.

unicheck screenshot

Unlike other tools, Unicheck has a singular mission, to detect and fix plagiarism and it does so impressively well. Although their primary target market is academics, they do offer a business tool as well. Pricing is quite affordable, even for those on a budget.


  • Affordable even for students on a budget.
  • Best for academic work.
  • Accurate.
  • Easy to use.
  • Doesn’t save your documents (privacy) in their database.

⛔️  CONS:

  • The free version limits you to 1 page.
  • Lacks advanced editing tools.

5. Duplichecker

Best Free Plagiarism Checker

Another great contender is Duplichecker, which works best for teachers, students, and budding, young writers. It’s completely free, so you don’t have to pay a dime to use it. To use Duplichecker, you only need to copy and paste your text in and click the button to run the process.

duplichecker screenshot

Some of the tools you can use with Duplichecker are a plagiarism checker, a word counter, spell checker, and grammar checker. The interface is a little old-school, but the system works well, and again, it’s entirely free to use. The only limitation is you can only check 1000 words at a time.


  • Completely free to use.
  • Great for students, teachers, and young writers.
  • Super easy to use.

⛔️  CONS:

  • Outdated interface.
  • Limited to 1000 words at a time.

6. Whitesmoke Plagiarism Checker

Great for Teachers and Students

Whitesmoke stands out as another excellent tool for both students and teachers. It checks content samples against billions of online websites to see if anything has been re-used, copied, or stolen. Although it is not as popular as Grammarly, it is efficient and effective, and the Word and Outlook integrations make it easy to use on the fly.

whitesmoke screenshot

Whitesmoke is a comprehensive program, also checking for grammar and punctuation. They claim that they “detect more errors than any other tool”. Whitesmoke is a Windows-based tool and works with all Microsoft-compatible software. It even translates text into 50 languages to boot.


  • Word and Outlook integrations.
  • Effective plagiarism detection.
  • Built-in translation tool.
  • Works on all web browsers.

⛔️  CONS:

  • Windows only, no apps for Mac.
  • Fairly expensive.

7. SmallSEOTools

Another very effective way to check your text for plagiarism is SmallSEOTools. It is not as powerful or effective as Grammarly, but it is free and includes some bonus features like a grammar checker, word counter, spell checker, paraphrasing tool, and a language translator.

They even have a whole cache of SEO tools to help with keywords and density when creating content geared towards website traffic building.

smallseotools screenshot

SmallSEOTools also includes some extensive backlink tools to analyze your website for SEO-friendliness, metadata resources, website tracking, proxy, and domain management tools. That is just the tip of the iceberg; this free service offers dozens of other helpful resources to enhance your website and make it easier to find on the web.


  • Completely free to use.
  • Dozens of add-on tools for SEO, word counter, grammar, etc.

⛔️  CONS:

  • Ad-heavy website.
  • Not super intuitive to use.
  • Not as effective as other plagiarism checkers.

8. Copyleaks

Everyone has competition, and Copyscape’s worst enemy is Copyleaks. Not only does Copyleaks scan the internet for any duplication of your content, but it also acts as a copyright protection tool. Even if your content comes out clean, you may find that your original text shows up elsewhere on the internet because someone borrowed it without your permission.

copyleaks screenshot

One of the strengths of Copyleaks is that it finds those indiscretions and points them out to you so you can address them. The program allows you to check 100 pages/essays at a time, so it works great for teachers. They have a mobile app and a language translator, but you are limited to only 2500 words in a month unless you pay for the premium version.


  • Check 100 pages at a time (great for teachers).
  • Mobile app included.
  • Built-in translations.
  • Copy protection tool.

⛔️  CONS:

  • The free version limits you to 2500 words per month.
  • Paid business plan limits you to 100 pages per month.

9. CheckForPlagiarism.net

The award-winning plagiarism tool built by computer scientists, academics, and writing professionals, CheckForPlagiarism.net, is trendy among teachers, students, researchers, and professional writers.

They offer a free and paid version, multiple languages, and they are endorsed by Verisign, The Better Business Bureau, and Truste. They value security and use SSL encryption, firewalls, and offsite backups to keep client’s data safe.

checkforplagiarism screenshot

CheckForPlagiarism has different pricing plans for different customers. For example, they charge students only $20, educators will pay $85, and professionals are charged $95 and up. These people take plagiarism very seriously, so if you want a tried and true service that values academic standards and will protect your content with top-notch security, this might be the tool for you.


  • Free and paid versions.
  • Endorsed by Verisign, The Better Business Bureau, and Truste.
  • Excellent security and backups baked right in.
  • Different pricing plans for students and businesses.

⛔️  CONS:

  • Pricey for educators and business professions.

10. Quetext

Although not the best plagiarism checker around, Quetext is a very good alternative. It is simple to use and offers a free trial. However, the free trial is limited to only 500 words.

Quetext compares documents against online sources and books but not scholarly articles, so it’s missing a big piece of the puzzle. That makes it much less useful for teachers and students.

quetext screenshot

It may work fine for other applications, but without an extensive database to compare text against, it might miss things that other plagiarism checkers will not. If your needs are simple, Quetext may work for you.


  • Built-in citation feature to help you cite sources correctly.
  • Free trial to test usage.
  • Somewhat useful plagiarism checker.

⛔️  CONS:

  • The free trial is limited to 500 words.
  • Must have a monthly subscription to use.
  • Will not check for plagiarism against academic articles and sources.
  • Some users complain about false-positive results.

11. Plagiarism Hunt

Plagiarism Hunt is another free online plagiarism checker that is actually an all-in-one tool that filters text through many of the top plagiarism checkers on Google like Turnitin, Unicheck, Plagscan, and RepostSEO among others. You can either copy/paste text into Plagiarism Hunt or upload a file.

plagiarismhunt screenshot

Your text will be tested for free against one of the online plagiarism checkers. You can see a detailed report for $6. If you want something tested against four of the top plagiarism checkers, you can pay $45. The terms are pretty straightforward, and the site simple enough to use.


  • Instantly see the plagiarism percentage.
  • Free to use for one of the checkers.
  • Low cost to see a detailed report.
  • Works on Windows, Mac, and mobile devices.
  • Submit files in multiple formats (doc/docx/pdf/txt).
  • Security - does not save your files on their server.

⛔️  CONS:

  • You can’t choose the checker to use when trying the free version.
  • Have to pay for detailed reports.
  • Sketchy credibility - the website is poorly written with dozens of grammatical mistakes.

What is a Plagiarism Checker?

A plagiarism checker is online software that checks a sample of text against thousands of online sources, books, academic articles, and scholarly papers looking for verbiage that has been re-used or stolen without permission. Good plagiarism checkers can find even nuances that indicate stolen content. Most charge a fee, but you can also use some plagiarism checkers for free.

Why Use a Plagiarism Checker?

Most people use a plagiarism checker to review content to make sure no part of it has been plagiarized. Sometimes academics use them to ensure that students have cited references and quotes correctly.

Benefits of Using Plagiarism Checkers

There are many benefits to using a plagiarism checker. The most common reasons someone would use a plagiarism checker are:

  • Ensuring the uniqueness and originality of content provided by others.
  • Checking your own writing to make sure you aren’t plagiarizing anyone else’s work.
  • Scanning for paraphrasing and re-using content without citing proper references.
  • Use the bonus tools like grammar, spelling, usage, wordiness, style, and punctuation correction.

Best Plagiarism Checker FAQS

What is plagiarism in simple words?

According to the Merriam-Webster online dictionary: to “plagiarize” means: To steal and pass off (the ideas or words of another) as one’s own. To use (another’s production) without crediting the source. To commit literary theft. In the simplest of terms, plagiarism is a fraud, and the consequences can be very serious.

What are the four types of plagiarism?

There are four different types of plagiarism: direct, self, mosaic, and accidental. Direct implies that the writer knew they were copying. If you re-use the content of your own that has already been submitting, that is self-plagiarism. Mosaic is when someone takes bits and pieces of a bunch of different articles and pieces it together to make it seem unique. Accidental is just that, someone forgets to cite a reference correctly or give credit to the original author.

What software can I use to check plagiarism?

There are dozens of tools out there, and the information may be confusing. To make things easier, check out our list of the best plagiarism checkers to help narrow it down to find the best plagiarism checker for you.

Which plagiarism checker is the best?

Most online users rate ProWritingAid as the best online plagiarism checker. Coming in a close second is Grammarly and following on its heels, Copyscape and Duplichecker. Some of these are free or offer free trials, and some require paid subscriptions.

Is there any free plagiarism checker?

Yes, there are a few free plagiarism checkers, but most carry limitations such as word count or how often you can use them. The paid versions are typically much more robust and helpful. Depending on what you need, there is probably a subscription plan that will work for you.

What is the best free plagiarism checker?

The best free plagiarism checker depends on what you need it for and how you intend to use it. Grammarly stands out as a leader in the industry, but you can also get good results using ProWritingAid and others like Copyscape and Duplichecker.

Is the plagiarism checker reliable?

Most top plagiarism checkers are reliable, but the accuracy level will depend on the checker you use. Some are better than others, and you might want to check reviews and compare stats before signing up for a plan.

What is a good plagiarism score?

Typically, you would hope for a 0% score, which would mean the entire document was plagiarism-free and completely unique. However, most editors and academics consider anything less than 15% to be okay in terms of acceptability.


Depending on your needs, one or a combination of the tools above should give you everything you need to make sure your content is error and plagiarism-free. Most will help you clean up any mistakes and enhance your verbiage so that you sound your best no matter what you are writing.

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