Top 10 Best AI Content Detectors: How Accurate Are They?

Can ChatGPT-4 create content that flies under the radar of the best AI content detectors? We decided to find out:

ChatGPT responded with this:

So… can ChatGPT-4 outsmart the best 10 AI detectors with the following text?

“Last weekend, I visited my grandmother’s old farmhouse, nestled in the rolling hills of the countryside. The air was filled with the sweet scent of wildflowers, and the only sound was the gentle rustle of leaves in the breeze. As I wandered through the overgrown garden, memories of summer holidays spent there as a child came flooding back. I remembered the hours spent climbing trees, chasing butterflies, and listening to my grandmother’s tales of her own childhood adventures in these very fields. It was a poignant reminder of the simple joys of life and the enduring power of family bonds.”

In this blog post, you will discover an in-depth comparison of the top 10 AI detectors…

… and see whether or not they can outsmart ChatGPT (or ChatGPT outsmarts them).

Best AI Content Detector Tools: Side-By-Side Comparison

Creating content with AI is great, it is more cost-effective and quicker than any human-generated content can ever be.

As such, it allows companies and individuals to produce more content with less time and effort. Therefore significantly improving productivity and companies’s bottom line.

Yet having content being actively detected as AI, is not great. It’s a risky business:

• Google actively penalizes low-quality AI-generated content, leading to decreased search rankings for a company and lost revenue.
• Educational institutions often pursue a zero-tolerance AI policy, putting the diplomas of many students at risk.
• According to a Nature study, people display a proven bias against AI-generated content and media.

In short: AI-generated content is here to stay, but it should never be identifiable as AI content. 

For this reason, a growing number of individuals and companies turn to AI detection and humanization. Those tools expose (or conceal) AI-generated content effectively.

• The good news? There are plenty of AI detector tools available. 
• The bad news? Sorting through all available options is challenging and time-consuming.

To help you with the process, we published an in-depth comparison of the 10 best AI content detectors (as of 2024) – and see if they can pass our ChatGPT test:

1. Undetectable.ai – Best Overall AI Detector And Humanizer
2. GLTR – Good for Detecting Older AI Content (ChatGPT-2)
3. Originality AI – Good Overall AI Detector
4. Writer AI Content Dector – Good for Small Writing Projects
5. Copyleaks – Good for Educational Institutions
6. ZeroGPT – Good for Freelancers
7. Winston AI – Good Accuracy
8. Sapling – Good for Agencies
9. GPTZero – Good User Interface
10. Crossplag – Good for Content Creators

In this post, we’ll compare and contrast the following in detail:

• Key features and capabilities
• Pricing (monthly and annual plans, free trials)
• Reviews (customer reviews, online ratings from G2 and/or ProductHunt) 

Disclaimer: Undetectable.ai is our solution. We’ve done our best to present the information evenly because we want you to make an educated decision. That said, we are proud of our software and built it with the AI detection features and ease that we’d want. Detect AI-generated text for free here.

1. Undetectable.ai – Best Overall AI Detector And Humanizer

Undetectable.ai has been featured in Business Insider, ABC, CBS, NBC, Yahoo Finance, Fox, Lifewire, and Nature. As of January 2024, Undetectable.ai boasts 4,000,000 users and a #1 AI detector rating by Forbes.

What makes Undetectable.ai special? Simple, the unique combination of AI detector and AI humanizer. 

A natural step after AI detection is the need to conceal AI detection, right? Undetectable.ai allows users to humanize (conceal) AI-generated content at the click of a button.

Additionally, undetectable.ai delves deeper into the fabric of the text, analyzing its structure, syntax, and stylistic elements. This allows the software more metrics to accurately quantify AI detection than other solutions.

The AI detection tool is engineered to handle text of up to 10,000 characters in length at a time, and its AI detection is free.

Pros

• Passes our AI test with flying colors: Accurately detects ChatGPT-4 text as AI.
• Free AI detection: The tool is free to use for AI detection. We only charge for AI humanization, which is a natural next step after AI detection for most use cases.  
• Easy to use: Instantly and effortlessly test the tool without any need to give your contact details. 
• Award-winning accuracy: Third-party tests report accuracy of 85-95%, making it one of the most accurate solutions available in 2024.

Cons

• The design of the tool may not suit everyone’s liking.

Reviews

5 out of 5 on ProductHunt

Pricing

AI detection is free. We only charge for the concealing of AI content. 

Our AI humanization plans start at $9.99/mo for 10,000 words – and range to $209/mo for 308,000 words if paid monthly (we offer a 50% discount on yearly packages). For enterprises with a need for a higher monthly word volume, we offer customized enterprise plans.

You can learn more about the pricing of Undetectable AI by clicking on the link.

Additionally, we offer an iron-clad money-back guarantee. If we humanize (conceal) the AI content and it’s still detected – we will refund the cost of humanization completely.

Click on the link to detect your first AI-generated text for absolutely free. You can also use the widget below (English only)- simply paste your text and see how easily it can detect AI-generated content.

Rated #1 AI Detector by Forbes

2. GLTR – Good for Detecting Older AI Content (ChatGPT-2)

GLTR, standing for ‘Giant Language (Model) Test Room’, is a free AI detection tool optimized for GPT-2. 

The code of GLTR is open-source, and the tool has direct access to ChatGPT-2 data. It works great for older versions of ChatGPT (2019) – but recent versions of ChatGPT will likely not perform as well.

Here’s how to interpret the test results, as the tool doesn’t offer clear percentage data:

• Green word: The word is likely generated by AI
• Yellow word: The word is probably generated by AI.
• Red word: The word is probably not generated by AI.
• Purple word: The word is not generated by AI.

To put our test in contrast, here’s a text generated by ChatGPT-2 and analyzed by GLTR:

As we can see, there’s a significantly increased detection of AI-generated text than with our ChatGPT4 text. 

Pros

• Passes our AI test
• Free AI detection

Cons

• Optimized for GPT-2, may not work as well for newer AI-generated content.
• No clear percentage score, the tool requires knowledge of statistics to interpret the results.

Reviews

No publicly available reviews so far of GLTR. 

Pricing

Giant Language (Model) Test Room (GLTR) is free to use.

3. Originality AI – Good Overall AI Detector

Originality AI is an online tool designed to detect AI-generated content. It aims to assist users, such as individuals or businesses, in identifying whether written content has been created by an AI – or a human.

Additionally, Originality AI also offers a built-in plagiarism checker. 

When it comes to AI detection, the software analyzes the content and provides a percentage score indicating the likelihood of the content being AI-generated. 

While Originality AI passed our test, we couldn’t access the full analysis of the content as it’s behind a paywall. 

Pros

• Passes our AI test
• Offers a Chrome extension
• Free AI detection

Cons

• Detailed results are behind a paywall
• Users complain about human-written content being marked as ‘100% AI’

Reviews

2.9 out of 5 on ProductHunt

Pricing

Prices start at $14.95/mo, which allows you to check up to 200,000 words for AI. If you need to check additional words for AI, you can buy separate packages that start at $30 for 300,000 words. 

4. Writer AI Content Detector – Good For Small Writing Projects

Writer AI is an artificial intelligence-powered writing assistant designed to help individuals and businesses improve their writing efficiency and quality. 

Additionally, it offers an ‘AI Content Detector’ that gives a detailed percentage of whether or not content is AI-generated. The detector is free to use up to 1,500 characters. 

Writer AI unfortunately didn’t pass our test, as it flagged our 100% AI-generated content as 56% human-generated. 

Pros

• Free AI detection
• Easy to use

Cons

• Didn’t pass our AI test

Reviews

No publicly available reviews so far of ‘Writer AI Content Detector’. 

Pricing

Writer AI Content Detector is free to use. But it only allows pasting of up to 1,500 characters.

5. Copyleaks – Good for Educational Institutions

Copyleaks is an AI detection software claiming 99% accuracy. Additionally, Copyleaks offers advanced plagiarism detection – which makes it a good fit for educational institutions.

The software uses sophisticated AI and machine learning algorithms to scan and compare documents against a vast database of online sources, academic papers, and proprietary content. 

Copyleaks may or may not pass our test, as we stumbled upon a paywall while requesting the results. 

Pros

• Advanced plagiarism detection

Cons

• Difficult to use: Requires sign-up to get the results
• Results are behind a paywall.

Reviews

4.4 out of 5 on Capterra

Pricing

Prices range from $9.99/mo for AI detection only on 25,000 words to $16.99/mo for AI and plagiarism detection on 25,000 words. 

6. ZeroGPT – Good for Freelancers

ZeroGPT is an AI detection tool that offers a free forever plan of up to 15,000 characters. 

The software has a simple interface, and doing the testing was easy. ZeroGPT allows you to request the results without any need for sign-ups. 

This makes the tool ideal for freelancers who require easy AI detection on irregular projects.

ZeroGPT passed the test, as it detected our content as AI-generated seamlessly. 

Pros

• Passes our AI test
• Easy to use
• Free AI detection on low-volume

Cons

• Pricing options may be a bit confusing
• Users complain about human-written content being marked as ‘100% AI’

Reviews

1.9 out of 5 on Trustpilot

Pricing

Prices for the paid plans range from $9.99/mo for up to 100,000 characters per month to $29.99 for the same character count (but with more words in ‘AI summarizer’ and ‘AI paraphraser’ tools).

7. Winston AI – Good Accuracy

Winston AI is a leading AI content detection tool to help check AI content generated with Large Language Models (LLMs) such as ChatGPT and Bard. 

Based on internal studies, Winston AI claims an accuracy of 99.98%. This makes it a very accurate AI detector tool. 

In our test, Winston AI does not initially pass the test, as the text is below 600 characters:

If we add ‘test’ at the end, we get to 600 characters. And then Winston AI (almost) passes the test:

While it’s true that the vast majority of the text was AI-generated, the ‘test’ was added by a human (me). So technically, the human score shouldn’t be 0%. 

However, the score of other AI detection tools barely changes when adding one word (it’s not enough data), so the test by Winston AI is still passed.

Pros

• Passes our AI test
• Smooth User Interface
• Free AI detection on low-volume

Cons

• Requires minimum character count of 600 to analyze text
• Test results are not 100% accurate
• Requires signup to see results

Pricing

Winston AI pricing ranges from $18/mo for up to 50,000 words to $29/mo for up to 200,000 words. Winston AI offers custom plans for companies that need larger volumes.

8. Sapling – Good for Agencies

Similarly to ‘Writer AI’, Sapling is a more general-purpose AI company for customer-focused teams. Sapling helps improve customer satisfaction by offering AI-generated personalized responses. 

Additionally, Sapling offers an AI detector that can spot content generated by popular AI-generation tools such as ChatGPT and Bard.  

While Sapling claims an accuracy of 97%, according to third-party tests, their AI detector scores a lower accuracy rate: 68% percent.

In our test, the AI detector proved to be very accurate. It rated our ChatGPT generated text as ‘100% Fake’. 

Pros

• Passes our AI test
• Free AI detection (up to 2,000 characters)
• Easy to use

Cons

• The design may not suit everyone’s liking.

Reviews

No publicly available reviews so far of ‘Sapling AI Detector’. 

Pricing

The Sapling AI detector is free for queries under 2,000 characters. Between 2,000 characters – and up to 8,000 characters – users pay $25/mo. 

9. GPTZero – Good User Interface

GPTZero is an AI-detector tool that offers additional features to humanize the content. This makes it similar to Undetectable.ai, which offers extensive ‘humanization features’ as well. 

The software also offers ‘deep scan’ features of the text that offer a word-by-word breakdown of the text. While you need to sign up for advanced plans to access all features, general AI detection is available without sign-up. 

Overall, GPTZero shines with its beautiful design and its slick user interface. It passes our AI test with a credible AI score of 98%. 

Pros

• Passes our test. 
• Beautiful design
• Offers a Chrome extension

Cons

• Requires sign-up (for advanced features, such as deep scan)

Reviews

4.2 out of 5 on ProductHunt

Pricing

Prices range from $15/mo for 150,000 words to $35/mo for 500,000 words.

10. Crossplag – Good for Content Creators

Crossplag’s AI Detector was trained on 1.5 billion parameters and it’s also great option of a detection tool.

It’s been recently updated to be more accurate, it has the capability of handling longer texts (up to 3,000 words), and is fine-tuned to reduce mistakes.

While highly effective, it’s not infallible, with accuracy influenced by text quality and length.

Pros

• Simple interface
• Advanced and updated algorithm to recognize AI text

Cons

• Difficult to use: Requires sign-up to get the tool

Reviews

2.9 out of 5 on Trustpilot

Pricing

Free for AI detection

Frequently Answered Questions

Can an AI Detector Detect AI Text With 100% Accuracy?

AI detectors can typically not detect AI-generated text with 100% accuracy. The accuracy of the tools in this article ranges from 68% to 99.8%.

AI detectors can most of the time detect AI-generated text, but the accuracy is not yet at 100%.

What Are The Key Features of AI Detector Software?

AI detector software relies on a range of features to detect AI-written text. Some of the key features include:

1. Machine Learning Algorithms: Most AI-content detection, similar to AI-content generation, relies on machine learning models. These are deep learning networks trained on large datasets of both human-written and AI-generated text.
2. Textual Analysis: The software analyzes various aspects of the text. These include word choice, grammar, coherence, and syntax. AI-generated text may also present easily identifiable factors like unusual phrasing or repetitive language.
3. Consistency and Context Checking: AI detectors often look for inconsistencies or context errors within the text. AI-generated text might include factual inaccuracies, contradictions, or irrelevant content that does not align with the overall context. These are also called ‘hallucinations’. 

Can Google Detect AI Content?

While Google has not publicized any change to its algorithm, every Search Engine Optimization (SEO) agrees that Google’s algorithms are sophisticated and constantly evolving. 

Google’s algorithms are designed to prioritize high-quality, relevant, and trustworthy content in search results. The key factor here is this: Are users happy with the content that they consume? Are they staying on the page?

Google’s search algorithms use a wide range of signals to evaluate whether or not users are indeed happy if they land on the given pages. These may include: 

• Bounce rate – are readers staying on the page?
• Total time spent on site – are readers consuming other content on the page after the initial content?
• Backlinks of the page – are readers sharing the content with their friends?

While these algorithms are not specifically targeted at identifying AI-generated content, they can indirectly impact the visibility of such content if it fails to meet Google’s quality standards.

What Is The Best AI Content Detection Tool Free?

The best free AI detection tool depends on your personal, organizational, or entrepreneurial needs. 

These 6 AI detectors have verifiably passed our difficult AI-generated content test and are free to use initially: 

1. Undetectable.ai
2. GLTR 
3. Originality AI
4. ZeroGPT
5. Winston AI
6. Sapling 
7. GPTZero

Out of these 6 tools, the following 4 AI detectors require no sign-ups and can be tested almost effortlessly: 

1. Undetectable.ai
2. GLTR 
3. ZeroGPT
4. Sapling 

We recommend starting with Undetectable.ai, as it offers a built-in humanization feature that allows you to automatically conceal AI content that is detected within the tool. While the humanization feature will cost you a few dollars, the AI detection can be done for absolutely free: Try Undetectable.ai risk-free today.