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Does the Copyleaks AI content detector work?

In our review of Copyleaks’ AI detector, we will run some tests to see if it is accurate.

We will also explain the extra features offered by Copyleaks and discuss their pricing and alternatives.

Testing Copyleaks AI Detector +Plagiarism Checker

First, let’s dive into testing Copyleaks with some AI-written content and then let’s see how it does with human-written content.

Signing up with Copyleaks is quite easy and you can use your Google account to make things easier.

I asked ChatGPT to give me an essay about Abraham Lincoln and then tested it out on Copyleaks’ platform.

The scan took about two minutes to run which is a lot slower than other tools like Winston AI

Here are the results:

Copyleaks correctly identified the text as AI content.

All well and good, but,

It turns out it is pretty easy to fool Copyleaks. All I had to do was adjust my prompt slightly. 

I asked ChatGPT to write me a “quirky” essay about Abraham Lincoln. 

Copyleaks failed to detect that the above text was written by ChatGPT. 

Now, I will test some human-written content from Wikipedia

The results correctly identified the text as plagiarised and correctly gave a score of 0% A.I content. 

After these tests, it is quite clear that their plagiarism detector works quite well but the A.I detector is easy to bypass. 

This was also noted in the research(a paper published on Arxiv) that CopyLeaks use as proof that their tool works.

In the study, the accuracy of Copyleaks A.I detection falls in half(from 100% to 50%) when the text is run through a paraphrasing tool like Quillbot. 

Comparing Winston AI and Copyleaks 

Winston AI correctly identified the”quirky” Abraham Lincoln article as AI

The reason for this is because of our datasets and methodology(You can read more about our openness to our accuracy rates in content detection here).

We at Winston AI created a large dataset of 10,000 texts to test the accuracy of their AI content detector. 5,000 texts were written by humans and 5,000 were created by AI systems like ChatGPT.

These human texts were carefully collected from diverse sources like essays, blogs, and Wikipedia before 2021. This avoids using AI-generated content from recent years.

The AI texts were created using the latest systems like GPT-3.5 Turbo and Claude with different settings to vary the output.

All texts were reviewed by humans to ensure high-quality data. The texts were also encoded properly to avoid errors.

We then tested our detector on this dataset. It correctly identified 99.98% of the AI texts and 99.5% of the human texts. This gave an overall accuracy of 99.74%.

Copyleaks’ Other Tools and Features

Here are some of Copyleaks’ other interesting tools and features: 

Codeleaks Source Code Detector

This is a tool that detects whether the source code was created by AI. This helps companies decide if their developers are using AI to write their code for them or not. 

Share Reports

This is a feature within the AI detector and plagiarism tool that allows users to share their reports. This is handy for schools or companies that wish to easily share their findings.  

Text Compare

Text Compare allows you to see two texts side by side so you can compare the writing styles and use of language. 

Cross-Language Compare

It is important to note that most A.I detectors focus on the English language. This tool helps you to compare texts to check for plagiarism across 30 languages.


Copyleaks also has integrations with popular LMS(Learning management systems) like Moodle, Canvas and Blackboard. They also have APIs that allow you to integrate their tools into your platforms and a browser extension. 

Copyleaks Pricing 

Copyleaks offers the following pricing for the use of their tools:

Monthly Price Yearly Price
AI Detector $9.99/month for 100 credits$8.33/month for 1,200 credits
Plagiarism $10.99/month for 100 credits$9.17/month for 1,200 credits
AI Detector+ Plagiarism $16.99/month for 1,200 credits$14.17/month for 1,200 credits

Copyleaks Alternatives

Here are some alternatives to Copyleaks:

Winston AI

Winston AI is the most accurate AI detector on the market with an accuracy rate of 99.98%. The tool is a premium solution for people looking for an AI content detector that works.

The difference with Winston AI is that we constantly keep our tool up to date with the latest LLMs on the market.

You can try out Winston here.

Originality AI

Originality.AI is another good alternative to Copyleaks that is aimed more at web publishers and content marketers.  

So the big question.

Is Copyleaks Good? Is it Reliable?

Copyleaks is a good plagiarism tool but its AI content detection tool is easy to bypass. It is not a reliable tool for Educators and Publishers looking to uncover if a piece of text was written by AI. 

From our testing, it was easy to use a different prompt to fool Copyleaks into thinking our AI written text was human-written. 

Conor Monaghan

Conor is an AI expert and English Teacher. He spends his time researching and writing about AI tools to help educators and publishers to become more productive.