Copyleaks vs ZeroGPT: Which is Better?

74% of all new web pages published in April 2025 contained AI-generated content, according to an Ahrefs analysis of 900,000 newly created web pages.

While that’s concerning, we now have tools fighting the spread of AI-generated content. Copyleaks and ZeroGPT are two of them. But are they good at it? And how do they perform in other areas where they operate?

This article finds out exactly that by putting each of the tools to the test. You’ll get an overview of both these platforms and also find out how their key tools performed in our hands-on testing.

Let’s start with a quick introduction to both platforms.

What is Copyleaks?

When Copyleaks started in 2015, it was only a plagiarism checker. Over the years, this plagiarism checker has built a strong reputation mainly in academic and professional writing. We’ll see how it performs in our tests later in the article.

After ChatGPT came and filled the internet with AI-generated text, Copyleaks added an AI detector to their platform, too.

Now, Copyleaks is best known as an enterprise-level tool, as its marketing seems to be aimed at schools and large organizations that need to run scans in bulk. 

Another thing that makes us say that is because Copyleaks offers integrations with Moodle and Canvas, both of which are popular learning management systems (LMS).

Aside from AI detection and plagiarism checking, Copyleaks has tools for grammar checking and content moderation.

Its AI detection is also multilayered. It has separate AI detectors for text and images. There’s also a deepfake detector.

What is ZeroGPT?

ZeroGPT is a copycat of GPTZero. It was launched in 2023, right after GPTZero became famous. The founders named the platform like that to capitalize on the success of GPTZero. 

Their trick worked for some time before people figured out that the two platforms are different. The name managed to fool even some big news outlets by making them accidentally mix up the two platforms in their reports.

That said, in essence, the tool is mainly an AI detector with a very simple interface. 

But it also offers a bunch of other AI-powered tools. Here’s a list of all of them:

• AI summarizer
• AI paraphraser
• Plagiarism checker
• AI grammar checker
• AI translator
• AI email helper
• AI humanizer
• Word counter
• Dictionary 
• ZeroCHAT (an AI assistant)

One unique thing about ZeroGPT is that you can use it in WhatsApp and Telegram.

ZeroGPT is also marketing an AI-powered photo background remover these days as “popular.”

Feature-by-Feature Hands-on Testing of The Tools

Both platforms have some overlap in the feature set. They both offer an AI detector, a grammar checker, and a plagiarism checker.

And they claim these tools to be the most advanced and accurate in their class. But we cannot take their word on the performance of their own tools.

So we performed hands-on testing of each one of them to see which platform is better than the other. 

Copyleaks vs ZeroGPT AI Detector

Copyleaks AI detector can scan 25,000 characters at a time. And ZeroGPT has a limit of 15,000 characters per scan. 

These are generous limits. So we decided to push the AI detectors to their max and test them with a lengthy text. 

Look at the text sample in the screenshot below. We uploaded some of our articles to Claude and tasked it to learn our writing style and write an essay on a random topic using that style. 

The result was a 12000+ word essay. The generated essay wasn’t entirely in our style and still had some AI patterns, but the text wasn’t very obviously AI either.

The entire essay was fed to the two AI detectors without any modifications. But the difference in the accuracy of the two was massive.

Result of Copyleaks AI Detection: Copyleaks flagged the entirety of the text as 100% AI.

Result of ZeroGPT AI Detection: ZeroGPT could only detect 30.8% AI text in the entire essay. It said our text is most likely human-written with some AI-generated parts. 

This was a relatively easier test. Both tools should have performed with high accuracy. But only Copyleaks did so. ZeroGPT was off the mark by a lot.

So Copyleaks’s AI detector is clearly better than ZeroGPT’s AI detector. 

But this was a simple test and against ZeroGPT only. 

How does Copyleaks perform when rigorously tested? We did this recently when we ran 3,000 text samples (half AI-written, half human) through Copyleaks, GPTZero, and Originality. 

Copyleaks had an overall accuracy of 90.7% compared to 99.3% accuracy of GPTZero. Copyleaks’s false positive rate was also high at 5.26%. At this rate, the tool would misidentify about 1 in every 20 human documents. Apply that to a class of 200 students, and you’ll have ten students dealing with wrongful accusations.

The same research also found that Copyleaks’s accuracy dropped to 60% on content that had been changed using a paraphrasing tool like QuillBot.

You can try GPTZero’s AI detector instead to avoid these inefficiencies.

Copyleaks vs ZeroGPT Plagiarism Checker

We chose a BBC article and one of our recent articles to test the plagiarism checkers of both platforms.

When we pasted the text into Copyleaks, the tool informed us that the max limit is 500 words. So we removed some words to make it less than 500 words and clicked the Check button. 

Copyleaks stayed stuck in the loading screen. The screen never finished loading, even after 10 minutes of waiting.

We assumed this could be because Copyleaks’s plagiarism checker is a paid tool, which is correct. Still, Copyleaks should inform users about that on the main page and shouldn’t market the tool as the “Free Plagiarism Checker”.

We still didn’t stop and bought the starter plan (which costs $16.99 per month) to test the plagiarism checker.

Some passages from the BBC article and GPTZero article were pasted into the tool. The results came as 100% plagiarism. Copyleaks accurately traced the text back to the two articles and other sources where the same BBC article was uploaded. 

Then we headed to ZeroGPT. Turns out ZeroGPT doesn’t allow checking plagiarism for free either. 

So we also bought its paid plan (which costs $9.99 per month) and scanned our text sample with it for plagiarism. ZeroGPT also accurately listed the two plagiarized sources in addition to two others. The only difference was that ZeroGPT’s text highlighting showing where certain passages were plagiarized from was slightly inaccurate. A few lines of the GPTZero article were attributed to the BBC article and vice versa.

Verdict: Both Copyleaks and ZeroGPT have accurate plagiarism checkers.

Copyleaks vs ZeroGPT Grammar Checker

The testing of grammar checkers didn’t take much time. That’s because Copyleaks’s grammar checker is a paid tool, so we couldn’t test it. 

And it’s not part of all paid plans. It only gets unlocked in the Education plan, which is for institutions and has a custom price. 

So that left us with ZeroGPT’s grammar checker only.

Luckily, ZeroGPT allows you to use it for free. 

To test it, we used some passages from the same essay that we used to test the AI detectors. But this time, the text was riddled with deliberate grammar errors.

Look at the original text below:

And here’s the same text but with errors, which I pasted into ZeroGPT’s grammar checker:

Below is ZeroGPT’s grammar and spell-checked version of the same text. One thing with ZeroGPT’s grammar checker is that it applies the corrections automatically. You don't have the freedom to choose which edits to keep and which ones to ignore.

Copyleaks vs ZeroGPT Pricing

The pricing structure of Copyleaks is very different from that of ZeroGPT.

Here’s an overview of the pricing before we get into details.

Copyleaks Pricing

Copyleaks uses a credit-based pricing model where one scan consumes 1 credit.  

There are two plans for individuals and small teams. Both these plans let you scan a text for AI and plagiarism in one interface and in one attempt. So both AI and plagiarism checker consume credits from the same pool. 

The number of words you can scan per scan also differs with the plan you choose.

Copyleaks has separate plans for the education and enterprise sectors. You’ll have to talk to sales to get a quotation for these plans. Both these plans have special perks like LMS integrations and dedicated support.

The education plan subscribers even get to scan for plagiarism, AI, and grammar in the same interface. 

ZeroGPT Pricing

ZeroGPT has a forever-free plan and multiple paid plans for both individuals and businesses. 

Users of the free plan have reported that it is riddled with constant advertisements on the page. There are strict limits on how much text you can scan at one time, too, which we also witnessed first-hand. 

There are three paid plans for individuals. 

The Pro and Plus plans are the same in a lot of ways. They both let you scan 100,000 characters per AI detection, and the words/scan limit of other tools is also the same.

The only big difference is that the Pro plan includes only one plagiarism scan for your entire subscription. In contrast, the Plus plan increases your plagiarism limit to 25,000 words every month.

The Max plan gives you the highest word limits for all their tools. It also gives you the ability to use ZeroGPT on Telegram and WhatsApp.

For businesses, there are two plans. Both of them have even higher word limits and allow access to the full suite of ZeroGPT tools. 

The Verdict: ZeroGPT is the cheaper choice of the two. Copyleaks is a more professional tool for people who need thorough reports and want to integrate the service into their schools or businesses.

Final Verdict of Copyleaks vs ZeroGPT Comparison

As per our tests, Copyleaks is clearly the better AI detector of the two. But when it comes to plagiarism checking, both perform accurately.

As for the grammar checkers, we could only test ZeroGPT. Copyleaks’s grammar checker was paid and part of the education plan, which is for institutions only. ZeroGPT’s grammar checker performed fine. But it wasn’t intuitive. You have to manually find all the changes it makes because it sometimes misses highlighting all the changes. Also, you don’t have control over approving or rejecting changes. The tool implements changes without asking for approval.

Coming back to AI detection, both platforms also lack deep reporting, and the level of accuracy that you would want for making big decisions in a classroom or workplace based on AI detection results.

So then what’s the alternative, you may ask?

You should use GPTZero if you want the most accurate and deep AI detection scans.

Our AI detector is officially recognized as the leading AI detector in the industry because of its performance on the RAID benchmark. 

Try GPTZero for free today and see the difference in accuracy for yourself.