Skip to main content

GPTZero is a tool that checks if a text was written by an AI tool like ChatGPT. In our opinion, it isn’t the best AI detector as it isn’t as accurate as Winston AI.

Try Winston AI here

What is GPTZero and Who Developed it?

GPTZero is an AI detector which is a tool that checks if a text was written by an AI tool like ChatGPT. 

GPTZero trained its model based on human-written and AI texts to learn which text is which. It uses machine learning formulas, Perplexity and Burstiness, to test how predictable the language is.    

The tool is being developed and worked on by Princeton student Edward Tian. 

Is GPTZero Reliable?

According to the GPTZero website, they correctly classify human-generated text 99% of the time and AI content 85% of the time. 

Testing AI Detector’s reliability is often quite difficult and many detectors are not open about the accuracy rates of their tools.

One problem is the sheer number of AI detectors and many tests include some detectors and exclude other tests. 

This study by Scribbr found that our tool Winston AI is the most accurate and reliable and GPTZero is not as reliable. 


Testing GPTZero for accuracy

Let’s test out GPTZero ourselves to see if it is accurate.

I asked ChatGPT to write me an essay about Oliver Cromwell and signed up for GPTZero to test it for AI detection.

Now let’s see what the results are:

So while it did a good job, it did say that there was a mix of human and AI text even though it was pure AI text.

Let’s test it out with our AI detector Winston AI which has a 99.98% success rate detecting AI written text.

As you can see the result is more clear cut.

After testing GPTZero with different models

(ChatGPT 4 Turbo, Claude 2) and different prompts, the tool did a good job of distinguishing AI content from human-written texts. 

What Are Good Burstiness and Perplexity Scores in GPTZero?

This depends on whether you are testing for AI-written content or human-written content. 

For AI detection (which is why most people use these tools), a low score on the Perplexity and Burstiness scales suggests that the content was written by AI.

In the image above you can see a scan that was correctly identified as an AI text. You can see that the perplexity and burstiness scores are at the low end.

GPTZero used to use perplexity and burstiness as part of their main detection results but many people found this confusing so they have now switched to a percentage model that shows the likelihood AI or Human written.  

GPTZero’s Extra Features

Apart from the AI detection tool, GPTZero offers the following products:

Chrome Extension

GPTZero has a chrome extension that allows you to scan text around the web. This could be handy for educators who need to check some AI text on Google Docs or some other content editing platform.

Human Writing Report 

Some students are being falsy accused of using AI to do their assignments. This human writing report tool allows you to show that your writing was written word by word and not copy/pasted from an AI writing tool.


The GPTZero API allows you to integrate AI detection into your platform. Documents are not stored that use the API call. 

Canvas and Microsoft Word add-on 

GTPZero is also available to integrate within Canvas and is available as an add-on for Microsoft Word. 

GPTZero Pros and Cons


  • Lower cost compared to some other tools per word scanned
  • Some useful extra features like the Human Writing Report
  • Free version available


  • Not as accurate with AI detection as a tool like Winston AI
  • I couldn’t find any information about GPTZero working in other languages
  • Doesn’t save scans so difficult to share

GPTZero Pricing 

The cost of using GPTZero is the following:

Pricing per monthWords Scanned 
Essential Plan$15150,000
Premium Plan $24300,000
Professional Plan$35500,000

There are savings of 33% if you sign up for a yearly plan. You can also test out the tool for free. 

GPTZero Alternatives

There are many AI detectors on the market, some have high accuracy rates and others don’t. Here are some of the top alternatives to GPTZero.

Winston AI

Our tool Winston AI is the most accurate AI detection tool with an AI detection rate of 99.98%. As you saw from the example above our tool gives a clearer result than a tool like GPTZero.  

Try Winston AI here


Copyleaks is another AI detection tool that attempts to check text for AI content and plagiarism. In our experience, the plagiarism tool works well but the AI detector is quite easy to bypass. Read more in our Copyleaks review here.


Turnitin is a plagiarism tool that was founded way back in 1998. They have recently added an AI detection tool and AI grading tool to their suite of tools. Unfortunately, some universities have stopped using Turnitin’s AI detection model due to its inaccuracy


Is GPTZero the best AI detector?

I think we can safely say that GPTZero is not the best AI detector out there but it certainly is better than many of the free AI checkers out there. 

In our opinion, Winston AI is the best AI detector because it is the most accurate. 

Frequently Asked Questions

How does GPTZero compare to Turnitin in detecting AI-generated text?

Turnitin is a plagiarism checker that is commonly used in academic institutions to detect plagiarism in student papers. GPTZero, on the other hand, is an AI content detector that is specifically designed to identify AI-generated text. While both tools serve different purposes, GPTZero has been shown to be effective in detecting AI-generated content, which is a growing concern in academia and beyond.

What is the significance of a ‘burstiness score’ in GPTZero?

The ‘burstiness score’ is a measure of how frequently certain words or phrases appear in a text. This score is used by GPTZero to determine whether a piece of text was likely generated by an AI model, as AI-generated content tends to have a higher burstiness score than human-generated content. The burstiness score is just one of the many features that GPTZero uses to detect AI-generated text.

Can GPTZero be considered the most reliable AI content detector available?

While GPTZero has received positive reviews for its ability to detect AI-generated content, it is difficult to determine whether it is the most reliable AI content detector available. There are many other content detectors on the market, and the effectiveness of these tools can vary depending on a variety of factors, including the type of content being analyzed and the specific AI models being used. However, GPTZero has received positive reviews from users and has been endorsed by reputable media outlets.

How do user reviews on platforms like Reddit and Trustpilot rate GPTZero’s performance?

User reviews of GPTZero on platforms like Reddit and Trustpilot are generally positive. Many users have praised the tool for its accuracy and ease of use, while others have noted that it has helped them detect AI-generated content that they may not have otherwise caught. Some Reddit users have also complained abot the accuracy of the tool.

What are the advantages of using GPTZero over ZeroGPT for AI detection?

While both GPTZero and ZeroGPT are AI content detectors, GPTZero has several advantages over ZeroGPT. For one, GPTZero is specifically designed to detect AI-generated content, while ZeroGPT is a part of a suite of other online tools. Additionally, GPTZero has a number of features that ZeroGPT does not, such as the ability to calculate a burstiness score for a piece of text. Overall, GPTZero is a more specialized tool that is better suited for detecting AI-generated content.

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.