How Accurate are AI Checkers? With Practical Examples

Just recently, Apple stepped into the AI game by putting OpenAI into its system with the announcement of iOS 18.

The tech giant is only one of the many more companies that have already joined in on the trend.

The way we carry out our everyday lives has changed forever since the rise of AI.

Aspects of our routines – from receiving personalized recommendations on our favorite streaming services to the advanced features right at the palm of our hands – technology really enhances the way we live.

However, AI is also a double-edged sword that can be both helpful and potentially misused.

Whether you’re a content creator or a professor, it’s important to be sure that the content you receive is authentic.

This is where the checkers come in – but are AI detectors accurate? We tried them out.

With hundreds of AI checkers on the market now, we know how choosing the right one can feel overwhelming.

So, we chose the best AI checkers and tested their accuracy.

Here’s your definitive look into just how accurate AI detectors truly are.

How Accurate are AI Checkers? A Data-Driven Answer

Without you realizing it, AI-generated content is everywhere – from articles to reports, creative writing, and much more.

AI tools have reshaped how education works, too, helping both students and institutions.

But with great power comes great responsibility. The use of AI in school raises some really big questions about authenticity and originality. This is where AI checkers come in.

Teachers, for example, use AI-detection software to see if students have used AI for their assignments.

AI checkers analyze the text that you feed into it for patterns, structures, and other elements that typically indicate AI content.

Once the text has been analyzed, the AI probability score will be provided.

It’s as easy as that. But while these tools can help, they’re far from perfect and have their own limitations.

Tests show that AI checkers vary in accuracy.

Tests show that AI checkers vary in accuracy.

They generally do better with older AI models like GPT-3.5, but they struggle more with advanced models like GPT-4, just because the newer model resembles human writing much more closely.

This can potentially lead to the occasional false positive, where someone’s work that’s made by them entirely is incorrectly flagged as AI content.

It’s a concern that’s been felt for a while now, leaving teachers still cautious when using these tools.

AI checkers are not a guarantee, so the best users can do is treat them as tools and not as the final verdicts.

It’s still incredibly helpful that these detectors can flag potential issues within seconds, which might take much longer with the naked eye, but always follow this up with a real human review to verify the results.

Be aware of the limitations of your AI checker so you can still maximize your efforts.

Examples of AI Checkers and their Accuracy

We tested the accuracy of some of the most trusted AI checkers available today.

There are so many out there, but we narrowed it down to Undetectable AI, Originality AI, Turnitin, and Writer.

To conduct our test, we used purely human-made and AI-generated content created using ChatGPT.

Just note that it’s a different case for Turnitin, where we had to adapt a different approach because it is a paid service for institutions.

But we still managed to gather some similar results.

Each of these checkers has its own detection method and scoring system for detecting AI content.

However, our goal stays the same: we want AI work to be detected as 100% AI and human content to be seen as 100% human.

Here’s how these tools performed in our tests so you can decide which one’s right for you.

Undetectable AI

Rated the #1 best AI detector by Forbes and trusted by over seven million users, Undetectable AI won’t let you down.

It’s considered the leading AI detector that also comes with a humanizer feature that matches human writing styles.

Undetectable has been updated to detect even ChatGPT-4 text as AI, making it very reliable – and the results show it.


With an accuracy rate of 85-95% on external tests, it’s still one of the best tools in 2024.

In our test, Undetectable was able to identify both AI and human-generated content. Its scoring system evaluates the “AI Detection Likelihood” for every AI language model.

Detecting human content with Undetectable AI

When it comes to both AI and human detection, it flagged everything with 100% accuracy.

While the results for human content were only considered 50% likely in some models, it was still impressive as the content was approved as confidently human.

This goes to show that Undetectable stays useful for bypassing AI detectors, combining both speed and quality in its text analysis.

Ensure that AI content is appropriately flagged while also having the option to humanize AI text when necessary.

Use the widget below to discover how Undetectable AI can elevate the quality of your texts (English only). Don’t waste time – use the widget now and feel the difference!

Rated #1 AI Detector by Forbes

Originality AI for teachers homepage

Probably one of the most popular AI detectors on the market is Originality AI.

Serving as both a plagiarism and AI content detection tool, it lets users compare text against any publicly available web content and run it through the AI.

According to Originality AI, their ChatGPT checker boasts 83-93% accuracy with a ~2% rate of false positives.

Regardless of the type of writing you test with Originality, the tool will display a percentage rating.

This will indicate the likelihood that the text was written by AI. It will also provide links to pages where it finds potential plagiarism violations.

Detecting AI content with Originality AI

Originality AI definitely showed its accuracy in flagging AI content with a 100% score. For human content, it returned an 82% human score.

Detecting human content with Originality AI

While this is less accurate than we expected, it still provides a reasonable amount of confidence that the content was purely human-written.


turnitin ai detector accurate

If you’re studying or working in a school, you’ve most likely already heard of Turnitin. This is a popular plagiarism detector most used in academic settings.

In addition to its plagiarism detection capabilities, Turnitin also has an AI detector that helps educators and other users identify AI-generated text in submitted works.

Turnitin claims that its tool is 98% accurate in detecting AI-generated content.

But because Turnitin is a paid service tailored for institutions, we couldn’t conduct our own test.

We have found some reliable results from a test done by BestColleges, which used a similar method to ours – testing both purely AI and human-written content.

Detecting human content with Turnitin by BestColleges

Their assessment shows that Turnitin was able to accurately identify AI-generated content and human-written content with 100% accuracy.

The tool was able to recognize a hybrid version and highlight which portions needed fixing.

Turnitin is an excellent tool for teachers, especially for those with access to it through their institution’s learning system.

However, it can also be quite difficult to learn and might require some training to master. It’s also expensive and typically limited to the school system only, making it not accessible to individual users.


writer homepage ai checker accurate

Writer is known for its wide range of writing assistant tools that are available through a paid monthly subscription.

But what’s great about the platform is that it offers its AI detection tool for free.

No need to sign up or pay fees. Just copy and paste your content and let it run on the platform.

The platform will then provide a percentage score of human-generated content, with 100% indicating that something is entirely made by a human with no AI involvement.

In our test, Writer was able to identify AI-generated content but with much lower confidence, nearly passing for a 50% score.

Detecting AI content with Writer

While it provided a more confident score for the human content, it still lacked the precision we were looking for.

Detecting human content with Writer

A writer falls short in terms of accuracy compared to the other AI checkers on our list, but casual writers who just want to check some work quickly can still benefit from its free scanning feature.


What is the best AI checker?

The best AI checker will still ultimately depend on the needs and preferences of the user. But you can’t go wrong with a reliable detector like Undetectable AI, which has already been tried and tested as a top choice for its high accuracy.

How do professors check for AI?

It’s no longer just the students. Professors now also use AI detection tools (like Turnitin if it’s already part of their school system) to check their students’ works for possible AI involvement. These tools are really good at analyzing text patterns and structures to identify AI content.

Do AI checkers require human verification?

While AI checkers can flag AI-generated content fairly accurately, some human verification is still needed to ensure accuracy and avoid false positives. Signs like having an inconsistent tone and the use of overly sophisticated language are some typical AI red flags.

What factors affect the accuracy of AI checkers?

Several factors can impact the accuracy of AI checkers, like how sophisticated the AI model is used to create the content or the algorithms used by the checker itself. There is also hybrid content that combines both AI and human-written content. This can make it harder to measure the accuracy of these tools.


So, how accurate is an AI checker? We have no definitive answer. Some do well, and others perform poorly.

The algorithms used to measure the scores play a role alongside other factors.

But while AI checkers certainly have their limitations, they’re still considered essential tools.

Let’s face it: some students will use AI in their work, so it’s best to be prepared.

If you’re a student or content creator, an AI checker is a great way to maximize your work’s potential through responsible AI use.

For your peace of mind, consider using Undetectable. Its advanced capabilities make it easy to spot AI-generated content, with a humanizer to always stay authentic.

Maintain the integrity of any written work on this all-in-one platform today.

Undetectable AI (TM)