Are AI Detectors Accurate?

As artificial intelligence writing tools evolve, so do the methods for detecting AI-generated content. But how accurate is an AI detector in distinguishing AI from human-generated content? 

AI detectors are not foolproof, but they are relatively accurate. Continuous advancements in AI writing tools create an evolving detection challenge, requiring ongoing in-house machine learning models and algorithms to keep up and verify human content.

In this article, I’ll explore AI detectors’ workings, reliability, and potential pitfalls, offering a comprehensive look at their accuracy and utility.

What you will learn

  • How AI detectors work and why they’re used 
  • The reliability of AI writing detectors 
  • Instances of false positives and their implications 
  • Tips to find a reliable AI content detection tool
  • Ways to humanize AI content to bypass detection

What are AI detectors?

AI detectors are tools that identify whether content is partially or entirely generated by artificial intelligence or written by a human.

AI detection tools use advanced language models to differentiate between AI-generated and human-written texts. They recognize subtle patterns that distinguish the calculated coherence of AI-written text from nuanced human writing.

The AI tool may assign a score to indicate the likelihood the words were AI-written, and some also highlight the text it predicts may have been AI-created. 

Here's how Surfer's AI detector showcases the results.

While you can legally use and publish AI-generated content, an AI detector helps ensure content is engaging and not repetitive. 

These AI tools are especially valuable when originality and content integrity are important.

You can use an AI detector tool when you: 

  • Must submit an AI originality report in the case of educational settings to maintain academic integrity 
  • Identify fake news and AI-generated spam 
  • Verify the authenticity of the content before publishing in a journal, magazine, or on the web
  • Must comply with regulations in the medical, legal, and financial fields to ensure authenticity and transparency 

How do AI detectors work?

AI detectors analyze text for patterns, structures, and characteristics unique to AI-generated content.

The process involves machine learning algorithms trained on vast datasets of human-written and AI-created text. 

By comparing the input text to these datasets, AI writing detectors can identify subtle differences in writing style, coherence, and other linguistic features that indicate the likelihood of AI authorship. 

A few other methods AI content detection tools use are: 

Embedding and analyzing word frequency, grammar, meaning, and nuances in writing. Since AI models don’t understand what words mean as people do, words and phrases are converted into numbers, and the tool uses high-dimensional data to create content. 

Perplexity, which assesses how predictable the text is based on the language model. Human content is more unpredictable than AI-generated text because of creative language choices. 

Burstiness, which refers to the variations in the frequency and length of sentences. When writing, you use varying sentence lengths and mix complex and simple structures, while AI text lacks variability, resulting in a more uniform text. 

Surfer's AI content detector uses text analysis, machine learning algorithms, statistical models, and probability scoring to distinguish AI from human-written text. 

Let's look at it in practice.

First, I asked ChatGPT to write 150 words on why you should regularly take your dog to the vet.

Then, I pasted the text into Surfer's AI detector. Surfer gave it a 100% AI score, which is the truth.

Surfer AI Detector showing 100% AI-written text.

When I reworked the text, it came back as 100% human-written.

Surfer AI Detector showing 100% human-written text.

How reliable are AI writing detectors? 

AI writing detectors have varying degrees of reliability, often depending on the specific tool and its underlying algorithms.

Factors such as the quality of the training data, the sophistication of the machine learning models, and the diversity of the language samples used in training all contribute to the accuracy of these detectors.

While not 100% accurate, AI detectors remain a helpful starting point for evaluating content authenticity.

An AI writing detector can’t ensure 100% accuracy because: 

  • These tools are still in their infancy but are becoming increasingly sophisticated. 
  • Every AI detector varies since each uses different training data. 
  • The lines between AI-written and non-AI-written content are becoming blurry since AI writing tools increasingly produce content that closely mimics human-generated text. 
Despite their limitations, AI writing detectors are useful for providing a preliminary assessment of content authenticity, but they should be used in conjunction with human judgment for the most reliable results.

Can AI detectors be wrong?

AI detectors can indeed be wrong, as they are not infallible. These tools rely on algorithms and training data, which may have inherent biases or limitations.

For instance, AI detectors might flag human-written content as AI-generated due to insufficient training on diverse writing styles or because of the nuanced nature of human language.

Here at Surfer, we ran an experiment using the Originality.ai detector. Originality.ai classified 28 out of 100 human-written samples as AI generated.

Now let's look at a concrete example using other AI detectors.

The US Constitution, written in 1789 and well before the advent of AI technology, has been flagged as AI-generated. I ran Section 3 of the document through ZeroGPT, which got a 100% AI-generated score. 

ZeroGPT flagging the US Constitution as 100% AI-created.

On the other hand, Surfer’s AI detection tool knew better, scoring the same content as 99% human-generated.

Surfer's AI Detector scoring the US Constitution as 99% human-written.

As you can see, choosing the right AI detector tool can make a huge difference. But more on that later on.

While AI writing detectors aren’t infallible, they look at language patterns and provide a probable score.

So, these tools should be a guide rather than a final judgment of content authenticity. 

What are false positives in AI detection?

A false positive occurs when AI detectors incorrectly identify human-written content as AI-generated.

byu/quelling from discussion

False positives are also more prevalent in shorter texts since the AI writing detector tool has less material to analyze.

These tools may also be biased against non-native English speakers, often flagging their human-written content as AI-generated. 

AI detectors can mitigate the risk of false positives by continually refining their models and incorporating a diverse range of writing styles and genres.

This includes training the detectors on content from various fields. By broadening their training datasets, AI detectors can be more accurate and reduce the occurrence of false positives.

How to find a reliable AI content detector

To find a reliable AI content detector, evaluate detection accuracy rates through user reviews, first-hand experience, and cross-checking results across multiple platforms.

Many AI detection tools offer free trials or versions, so take advantage of these to test the tools yourself.

For instance, Surfer's AI detector can analyze up to 595,248 words for free.

Pay attention to the detection accuracy rates and see how consistently the tools identify AI-generated content.

Cross-checking results across multiple platforms can provide a more comprehensive assessment.

Copying the same human-written blog post section into five AI detection tools gave me different results. 

It was a 99% human-written pass from the Surfer's AI detector.

Cross-checking content with Surfer AI detector.

GPTZero didn’t agree, detecting AI-generated content at 51.61%.

Cross-checking content with GPTZero.

Copyleaks states it’s human written, and so did Quillbot and Writer AI content detector with a 95% human-generated score.

Cross-checking content with Copyleaks.

By cross-checking the content, you can see that the Surfer's AI detector is quite accurate.

Additionally, consider the tool's ease of use, support, updates, and whether it offers additional features, such as the ability to humanize text.

By thoroughly evaluating these factors, you can select a reliable AI detector that best suits your needs.

How to bypass AI detectors 

You can bypass AI detectors by humanizing your content.

Here are some tips to humanize AI text:

  • Add personal anecdotes or unique insights
  • Vary sentence lengths and structure
  • Use idiomatic expressions and colloquialisms 
  • Write like you speak 
  • Avoid repetitive phrases 
  • Use paraphrasing tools, like Surfy to rephrase the content
  • Hire a human editor to review artificial intelligence content and identify areas that need revision and improvement.   

Additionally, you can also use a humanizer tool, such as the Surfer AI Humanizer, to make your text more natural-sounding.  

Here's how the Humanizer works.

First, I asked ChatGPT to create content about how to care for indoor vining plants.

Surfer's AI detector rated the text as 99% AI-generated.  

Example of AI-written text.

Then, I simply clicked on Humanize. As you can see, the humanized text has varying sentence lengths and a more conversational tone. 

Example of Surfer AI Humanizer at work.

Key Takeaways

  • AI detection tools use machine learning models and extensive datasets to analyze text patterns, differentiating between human and AI-generated content.
  • Understanding how AI detection tools work and recognizing their potential for error can help you use them more effectively.
  • While the technology continually advances, AI detectors are not entirely accurate and can produce false positives, where the tools flag human-written text as AI-generated.
  • Adding personal touches and practical scenarios can help bypass detection, enhancing the authenticity of AI-generated content.
  • To find a reliable AI content detector, consider detection accuracy rates based on user reviews, personal trials, and cross-referencing results across different tools.
  • Use AI detectors as a starting point, but always review the results and content manually for the most reliable assessment of authenticity.


AI detectors are valuable tools for identifying AI-generated content but aren’t without limitations. As AI writing tools evolve, so must the algorithms that detect AI text. 

By understanding how AI detection tools work and recognizing their potential for error, you can more easily bypass detection and ensure you use reliable AI content detection tools. Use an AI detector as a starting point, but review the results and content manually. 

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