ResourcesContent ToolsDuplichecker review: Still the Best content plagiarism detector? 2023 Update

Duplichecker review: Still the Best content plagiarism detector? 2023 Update

Duplichecker Review - 2021 update

This article has been updated for 2023. 10 years have passed since we first reviewed Duplichecker in 2013. The tool has changed since then. Is it still good?

First things first, Duplichecker is no longer just a plagiarism detector – it’s also an AI content detector, so not only can it tell you if your writing has been plagiarised, it’ll also tell you if ChatGPT or some other AI tools have written it.


Duplichecker, you say?

Yes, and you can check it out at

Duplichecker is an online content plagiarism detector with copy and paste and URL functionality. Less well known than Copyscape, Duplichecker offers the ability to check content for plagiarism through copy and paste or by uploading a .doc or .txt file.

Here’s what the plagiarism tool looks like:

Duplichecker Screenshot 2021

You can upload 1,000 words of content per search, making it ideal for checking articles that you have had written for your business.

Duplichecker features

  • 100% free
  • 1,000 words per search
  • Copy and paste
  • .tex, .txt, .doc, .docx, .odt, .pdf, .rtf file upload
  • URL check
  • 100% detection rate, 95% quote success rate (in our tests conducted in 2021)

Duplichecker Pro features

  • No ads
  • 10,000 words per search
  • Customer support and help

What’s it like?

Duplichecker is one of many content plagiarism detectors available online.

100% free to use, Duplichecker sets itself apart from the competition by offering the ability to instantly upload text in a variety of formats.

Compared to Copyscape and Plagspotter, Duplichecker returns a good rate of plagiarism detection.

Duplichecker is so simple to use that anybody can use it. Content marketers, content writing agencies, business owners, students; no matter who you are Duplichecker is accessible for all.

Ahh, but I bet it costs money down the line?

Nope, not a penny. It’s free.

Does it work?

Yes, it does, with a 95% to 100% success rate.

In order to test the plagiarism detection rate in Duplichecker, we carried out two tests a total of 15 times each.

The first test involved copying a 100-word paragraph of text from a Google, Yahoo and Bing indexed article and pasting it within a unique 1,400-word article. We then uploaded the text to Duplichecker and pressed submit.

The second test involved copying just 40 words of text and pasting it into a 1,460-word article.

The result?

Duplichecker passed with a result of 100%, pointing us directly to the very web page from which we copied the text, and it also highlighted lesser sources who either quoted or copied text themselves.

This was an astounding result and proof that the tool can be trusted by marketers.

We did find that Duplichecker’s detection rate fell to 40% when just 20 words were uploaded, however, we never expected the tool to be able to detect that low level of plagiarism.

95% success rate for quotes

Duplichecker handles quotes with a 95% success rate.

The 5% miss rate came about when we used very short quotes.

For example, the quote “Problems are not stop signs, they are guidelines” pasted into a unique 900-word article returned two results. This quote from Robert H. Schiuller is used in thousands of articles online. We had the same results with another 3 quotes.

Does this matter? Not really.

You see, quotes are quotes. It’s impossible to plagiarise a quote because it is impossible to use a quote without writing it word for word.

If you do use quotes in your content, link to the source. And if it’s a famous saying, don’t sweat it.

But what about Copyscape?

Copyscape is the number one content plagiarism detector online. However, in order to be granted the ability to upload text, you need to sign up to Copyscape Premium, a paid service (it costs 5 cents per search in USD). This is expensive when Duplichecker is free.

At Content Hero, we have signed up to Copyscape, but we use Duplichecker more for copy and pasting because it is free and it offers the exact same results.


Thumbs Up Review

As a free tool, Duplichecker is a valuable resource. Our own tests have found that it offers as good a detection rate as Copyscape Premium and that alone is a good enough reason to use it.

That said, Duplichecker is not the be-all and end-all of plagiarism detection. As a content marketer, utilising all available resources close to you is recommended. Other top services include Copyscape, Plagspotter, Doc Cop and Reprint Writers Tool. With each of these tools at your disposal, you’ll never make the mistake of publishing a low-quality article online.

Jakk Ogden is the founder and CEO of Content Hero.

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