12 Best AI Detectors in 2024: From Over 180 Tests (Updated)

Updated on January 15, 2024

My Overall Pick

Originality AI LogoPin

Originality AI

Originality.AI is the best overall AI detector with the highest accuracy.

Runner Up

Winston AI LogoPin

Winston AI

Winston AI is the runner-up AI detector with features like OCR.

Best Free

Passed AI LogoPin

Passed AI

Passed AI offers an excellent 100% free AI detector Chrome plugin.

You were probably thinking, “Can Google detect AI content?” right?

With the rise of AI writing software, it’s only a matter of time before search engines catch on.


Because AI-generated content lacks creativity, personality, context, and factual accuracy most of the time.

Over 63% of professionals struggle with bias and accuracy using it.

And that isn’t valuable to real human readers.

Do you really want to risk it?

I ran over 180 accuracy tests and ranked the best AI detectors to:

  • Avoid spam detection
  • Increase rankings
  • Improve user experience

Check the results.

What Is the Best AI Detector?

Best AI Detector BadgePin

Here are my top 12 picks for the best AI detectors.

Best AI Detectors Comparison Table

AI DetectorAccuracySubscription PlansRating (Out of 5)Website
1. Originality AI93.3%Monthly subscription or Pay as You Go4.7Try Now
2. Winston AI86.7%Monthly subscription4.3Try Now
3. Passed AI70.0%14-day free trial, paid plan after3.8Try Now
4. Sapling66.7%Free3.3Try Now
5. AI Detector Pro66.7%Free up to 3 reports, paid after3.3Try Now
6. GPTZero60.0%Classic is free, the other plans are not3.0Try Now
7. Crossplag53.3%Free2.7Try Now
8. Writer46.7%Free2.3Try Now
9. Content at Scale40.0%Free2Try Now
10. Kazan SEO40.0%Free2Try Now
11. GLTR26.7%Free1.33Try Now
12. Hugging Face26.7%Free1.33Try Now

Note: If you want to understand how I tested AI Detectors, it will be explained towards the end of the article.

1. Originality AI

Best Overall AI Detector

Originality UI Best AI Content DetectorPin

Originality.AI is an AI-detection and plagiarism checker tool targeted toward serious content publishers.

My test shows they are currently the most accurate AI detector with an accuracy score of 93.3%.


They accurately predicted 14 out of the 15 test samples I ran.

Note: The results are based on my independent tests. Yours might vary.

It also offers very generous team features, API integrations and pay-as-you-go payment structure.

If you’re a creator who runs a blog with a team like me…

This will be your top choice.

Key Features

  • Perform a complete website AI content and plagiarism audit with a button click.
  • Can accurately detect AI-generated content from tools using GPT-3, GPT-2, GPT-NEO, GPT-J, ChatGPT, GPT 3.5 (DaVinci-003), and GPT 4 with a success rate of 99%.
  • Able to detect paraphrased content with 95% accuracy.
  • Text highlighting to identify the specific sections that triggered the AI detector.
  • Integrate your Originality.AI data into custom applications with their API.
  • Add and remove unlimited team members while managing individual access through a single dashboard.
  • Brand new readability scoring method congruent with top articles on Google SERPs.
  • Detect AI-generated content on any website and Google docus with their free Chrome extension.


  • Very simple to use a checker that gets the job done
  • Highest accuracy among all the AI detectors on this list
  • Extremely reasonable pricing for the quality you are getting


  • It only supports English at the moment
  • Can’t export reports


Originality.AI Pricing PlansPin

Originality.AI currently only has one pricing model.

It costs $0.01 per credit, where one credit scans 100 words.

That means a 2500-word article will only cost you $0.25.

2. Winston AI

Best Originality Alternative

Winston AI HomepagePin

Winston AI just missed the top spot with an accuracy score of 86.7%.

It’s one of the newer AI content detection tools. But packed with a ton of unique features that most of the detectors on this list lack.

Originality AI currently wins in accuracy by just a margin.

They are extremely similar…

But Winston AI can detect AI images with Optical Character Recognition (OCR) technology. Originality can’t.

I use both in my content creation process because you can’t just rely on one tool.

You wouldn’t trust only one doctor’s diagnosis if you had a critical illness.

Read my full Winston AI review.

Key Features

  • Their model was fine-tuned on AI-generated content from popular tools like GPT-4, GPT-3, ChatGPT, Jasper, Copy AI, and more.
  • Tested on other NLPs such as AL21Lab’s Jurassic-1 model and still boasts an average 99% AI accuracy detection.
  • Extract text from scanned documents, pictures, and even handwritten notes using OCR technology.
  • Has an AI prediction map that shows inline text highlights analyzing the predictability.
  • Includes a Flesch-Kincaid Readability Score to evaluate the readability of your content.
  • You have the option of having detailed printable PDF reports.
  • It included Copyscape plagiarism integration as well.


  • Very professional user interface and smooth user experience
  • Only one with OCR integration at the moment
  • Email and chat support


  • A very new company, so they are still heavily in the development phase
  • It can’t scan using URLs at the moment


Winston AI Pricing PlansPin

Winston AI offers the following pricing plans:

  • FREE: $0 per month
  • GROWTH: $14 per month if paid annually. $18 if monthly.
  • CUSTOM: Contact their team

Start your 7-day FREE Trial with 2000 words with my link below. No credit card is required.

3. Passed AI

Best AI Content Detector Chrome Extension for Academic Institutions

Passed AI HomepagePin

Passed.AI is the ultimate solution for educators to prove that submitted work is either student-written or AI-generated. 

It leverages Originality.AI‘s accurate AI detection algorithms API and other leading NLP models to detect plagiarism and cheating.

Passed.AI ensures the highest level of AI detection through an entire document audit trail to decipher the exact activity used to create the content.

No other tool can match its enforceability.

Key Features

  • Document History Audit: Check the naturality through a replay function that tracks document activity metrics like changes, inserts, deletes, and alterations. 
  • Multiple Language Models: Capture a broad spectrum of AI content created by popular models like GPT-3, GPT-3.5, GPT-2, GPT-J, and GPT-NEO with a 94+% accuracy.
  • Military Grade Security: Ensure all your private information is safe with military-grade 256-bit encryption.
  • LMS Integration: Improve learning outcomes by integrating Passed.AI audit feedback with your LMS via their REST API (Incoming feature).


  • Check Google Docs directly with the Chrome extension
  • Unique document history audit system to promote enforceability
  • Future ChatGPT integration to assist with grading and marking


  • It doesn’t work with other long-form editors
  • Wasn’t trained on proprietary datasets


Passed AI Pricing PlansPin

Passed AI offers the following pricing plans:

  • STARTER: $12 per month
  • TEACHER: $35 per month
  • INSTITUTION: Contact their team

Start your 14-day free trial now. Get a full refund within this period if you’re unsatisfied.

4. Sapling

Best Free AI Content Detector

Sapling Ai Content DetectorPin

Sapling is an AI messaging assistant for Customer-Facing Teams. 

Still, the team has developed a free AI content detector that is surprisingly quite good and up-to-date.

Key Features

  • Super easy to copy and paste, and bam, you get the results.
  • Able to accurately detect AI written content by recent language models like GPT-4, GPT-3.5, and ChatGPT.
  • You can scan an entire average-length blog post up to 2500 from my testing.


  • More updates are coming despite being a free tool and not their main product
  • Can scan an entire article of average length


  • Requires 50 or more words to give an accurate reading
  • AI detector may not be fine-tuned with the relevant web copy


Sapling’s AI Content Detector is entirely FREE.

5. AI Detector Pro

Best AI Detection Suite

AI Detector Pro HomepagePin

Another AI detection tool?

Wait… You’re gonna like this one.

AI Detector Pro doesn’t just scan for AI-generated content, but it’s an entire suite equipped with whole bunch of other useful tools and utilities.

Forget about jumping between other sites before publishing.

Just do it all in one dashboard.

Key Features

  • Massive Tool Suite: Get over 30+ research, development, and content tools to support your AI content analysis.
  • URL Scanner: Get a full breakdown of a website page using just the link.
  • Sentence Highlighting: Get inline reports about AI likelihood for words and sentences.
  • White-label Report Exports: Print out all your content scans as a PDF with your own custom branding to share with stakeholders.
  • API Access: Integration AI Detector Pro into your own software tools at $0.09 per unit (1 unit is up to 4000 characters).


  • Money-back guaranteed if detection is inaccurate
  • Conduct research, development and content activities in one place
  • Figure out exactly which sentence is AI


  • Only supports English
  • The free plan is extremely limited


AI Detector Pro Pricing PlansPin

AI Detector Pros has these plans:

  • FREE: $0
  • BASIC: $13.99 monthly
  • UNLIMITED: $24.99 monthly

Use the code and sign up using my link below for 50% off.

6. GPTZero

Best for Detecting AI Content in Academia Niches

GPTZero HomepagePin

GPTZero allows you can easily spot fake text in academia and highlight the sentences likely to be AI-written.

It was trained on a large corpus of human-written text that spans student-written articles, news articles, and question-and-answer datasets across multiple disciplines in the sciences and humanities.

With over 1 million users, it’s quite an impressive feat by the Princeton student and founder Edward Tian.

Key Features

  • Unique Scoring Markers: Uses perplexity and burstiness to measure randomness and variation in the randomness of text, which are generally high for human-written text and low for AI.
  • Text Highlighting: Provides a holistic score for how much of the document is written by AI with text highlights.
  • Enterprise Solutions: Offers batch uploads for multiple files, API access for organizations, and support for setup and integration.


  • Fine-tuned detection models for education on paid plans
  • One of the better free data-backed AI content detection tools
  • Can classify 99% of human-written articles correctly


  • Only able to detect AI-generated content with 85% accuracy
  • Can only detect English content


GPTZero Pricing PlansPin

GPTZero offers the following pricing plans:

  • GPTZero Classic: $0 per month
  • GPTZero Educator: $9.90 per month
  • GPTZero Pro: $19.90 per month

7. Crossplag

Best for Academic Integrity

Crossplag AI Content DetectorPin

Like Originality.AI, Crossplag has a plagiarism checker and AI content detection features.

Originality operates on a credit system, while Crossplag is free to use.

The team seems to be positioning the tool toward academic integrity and enterprise usage.

Key Features

  • It’s based on a fine-tuned model RoBERTa using OpenAI’s massive dataset.
  • Shows a percentage probability scale to determine if the content was human-written text or AI-generated.
  • No sign-up is required. Just paste and check.


  • Completely free AI detection tool
  • Potential academic applications
  • Active development from the team


  • It only supports English content for now
  • Can only scan up to 1,000 words at a time
  • Still in beta, so it might not be as accurate


Crossplag’s AI detection tool is FREE to use.

8. Writer

Best for API Integration

Writer AI Content DetectorPin

From their name, you can guess that Writer is an AI writer tool that helps you…well, write content – duh.

To stay competitive, it’s also reasonable to expect they would have an AI content detection tool for their users to check for AI-generated text.

And similar to other tools, theirs also show a content score as a percentage.

Key Features

  • Able to detect content by GPT-3 and ChatGPT with superb accuracy.
  • No frills way of analyzing your text by simply pasting it in a box and getting a score.
  • Built into their content creation service, plagiarism detection, and many others.


  • You can request an API key to integrate with your app, but you must be on their team plan
  • Near-perfect scores for a free tool
  • Able to detect new AI content from models


  • It can only analyze up to 1,500 characters or roughly 300 words at a time
  • The tool bugs out sometimes and scans lesser than advertised


Writer’s AI Content Detector is entirely FREE.

9. Content at Scale

Best Built-in AI Detector With Content Generation

Content at Scale AI Content DetectorPin

Content at Scale is one of the new guys on the block offering an excellent 100% free AI detector.

It can check for AI-generated content made by GPT-3, ChatGPT, and other AI models with decent accuracy.

However, if you are also looking for a one-click solution to get full blog articles that are search engine optimized, plagiarism free, and pass AI detection, check out my full Content at Scale Review.

Key Features

  • The software was built by content marketers, copywriters, and SEOs with decades of experience.
  • Can produce AI-generated content that passes detection.
  • Text highlighting and other probability metrics to identify certain flagged areas.
  • Combines various proprietary natural language processing neural networks on top of GPT-3 through ensemble learning.
  • Able to detect more nuanced writing structures and phrases than free tools.


  • Not reliant on only GPT models
  • Line-by-line analysis
  • Supports over 100 languages
  • You can enter a maximum of 25000 characters


  • No reporting mechanism
  • Not as accurate as the paid options on this list


Content at Scale’s AI detection tool is completely FREE.

10. Kazan SEO

Best for Detecting Bulk AI Content Through URL

Kazan SEO AI DetectorPin

Kazan SEO is an entire SEO toolkit that includes an AI content detection tool as one of them.

Outside of AI detection, they have a content optimizer, text extractor, keyword clustering tool, and many other SEO tools.

Key Features

  • Easy-to-use UI with visual indicators showing whether the content is human-written text or AI-generated.
  • Bulk import URLs to automatically scan them for AI-generated text.


  • Produces one of the more accurate scores compared to the other free tools on this list
  • You can jump in between other SEO tools with ease
  • Able to bulk-check AI content


  • You need to input a minimum of 200 words to give accurate readings
  • It can only scan about 400 words or 2500 characters at a time


Kazan SEO AI Content Detector is entirely FREE.

11. GLTR

Best for Detecting GPT-2 Content Scientifically

GLTR AI Content DetectorPin

GLTR (Giant Language Model Test Room) is an AI detection tool created through a collaboration between MIT-IBM Watson AI Lab and Harvard NLP.

It was trained on the GPT-2, 117M language model from OpenAI to analyze text and determine how likely a human-created content was.

The tool assigns probabilities to each word by comparing text inputs to what GPT-2 would have produced instead and highlights them using different colors.

If there is a lot of text in Green and Yellow, it’s likely AI-generated text.

But if there is also a lot of Red and Purple text, it’s more like it is human-written.

Key Features

  • It produces text highlights to indicate whether it’s AI or human text.
  • A scientific tool that provides forensic analysis of a language model’s text input.
  • Created by brilliant research scientists and professors from MIT, Harvard, Cornell, and IBM.


  • Visual feedback, which is rare compared to even more recent AI content detection tools
  • Multiple metrics like probability tables and histograms to justify results
  • Scans GRE texts with complex words to detect AI-generated content


  • An outdated model that is trained on an old dataset like GPT-2
  • Unlikely to detect AI content accurately that was generated by newer language models


GLTR (Giant Language Model Test Room) is entirely FREE.

12. Hugging Face

Best Open Source GPT-2 AI Content Detector

Hugging Face AI Content DetectorPin

Hugging Face is a huge AI community that focuses on democratizing artificial intelligence through open source and open science.

Digging hard enough into their repositories, you can find a decent AI content detection tool.

Key Features

  • Easy to use interface by copying and pasting your text into the input box.
  • Produced by a niche machine learning community.


  • Can detect AI-written content by GPT-3 and chatGPT


  • Trained on GPT-2 data, so newer topics and writing styles might not produce accurate results


Hugging Face AI Content Detector is entirely FREE.

How I Test AI Detectors?

In this article, I have tested 12 different AI detector tools using the same texts and scoring system. Some of these tools are free, while others come with paid plans.

1. Performance Metrics

I used the following metrics to summarize the performance of an AI detector tool:

  • True positive (TP): AI-written text is predicted by the tool as fake.
  • True negative (TN): Human-written text is predicted by the tool as human.
  • False positive (FP): Human-written text is predicted by the tool as fake or AI-made.
  • False negative (FN): AI-written text is predicted by the tool as human.

2. Diverse Dataset

To make the comparison fair, I used different types of texts that cover different topics. Two topics are technical, while the remaining three are general blog articles

These are the texts used:

  • Blog article titled 10 Kinds of Phobias You Might Not Heard Of
  • Blog article titled How Fast Does Pothos Grow?
  • Blog article titled What Are the Advantages and Disadvantages of WiFi for Home Automation?
  • Journal paper titled Development of A Low-Cost Chlorophyll Meter
  • Introduction to a thesis paper titled Wireless Sensor Network Application in Precision Agriculture

For the AI-generated texts, I used GPT-3.5 and used the same prompt. For instance, I asked chatGPT to “write content about growing Pothos plants and tips.”

However, I added additional prompts for the technical papers to produce the desired content. 

For example, “include in the abstract that the prototype’s coefficient of determination is 0.8276 when compared with results from SPAD-502 and spectrophotometer.”

3. Training and Testing

Each of the 5 texts is between 1200 to 1800 words. To test the performance of the AI detector tools, I created additional variations of each text and categorized them as follows:

  • 100% human
  • 100% chatGPT 3.5
  • 50% human, 50% chatGPT

Overall, I have tested a total of 15 text samples.

Note: I didn’t test GPT4 because that requires a Plus subscription, and the majority won’t have it.

4. Accuracy Scoring

The accuracy score is defined as the total number of correct predictions divided by the number of data.

The following formula is as follows:

Accuracy score = (TP + TN)/ total number of texts tested

Where TP is the total number of true positives, and TN is the total number of true negatives.

For example, if a text has a TP of 9 and TN of 4, then it would be computed as:

Accuracy score = (9 + 4)/ 15 = 0.8666 or 86.7%

5. Rating score

Each AI detector tool is initially assigned a perfect score of 5 to get the rating score. Whenever it outputs a false positive or false negative, the score is subtracted with 0.3.

What Are AI Detectors?

AI Detectors (AI Content Detectors or AI Text Detectors) are software tools that use artificial intelligence to determine if a piece of text content is written by a human or another AI tool like ChatGPT. They usually show an accuracy score to illustrate their confidence in whether AI partially or entirely wrote it.

What Is the Best Free AI Detector?

The best free AI content detector is Sapling which had an accuracy score of 66.7% based on my testing.

It was developed by former researchers at the University of California Berkley, Stanard, and Google.

Another honorable mention is Paraphrasingtool.ai.

It’s able to detect GPT-4 content with decent accuracy given that it’s a free tool.

Are AI Detection Tools Worth It?

You don’t want to create content blindly with AI only to be penalized by Google in the future.

AI detection tools are also worth using to ensure AI text is humanized.

I’ve worked with many freelance writers, and it’s my first line of defense against their lies.

Some blatantly use AI writers even when they tell you they don’t.

And besides, most of the tools on this list are free, so there is no excuse not to use them.

Why Is It Important To Detect AI Content?

By detecting AI content, we can ensure that the information we view and interact with is authentic and accurate.

Here are other practical applications:

  • Preventing Google from flagging AI content as spam.
  • Preventing employers from getting ripped off by writers who say their content is original.
  • Ensure that the writing makes sense and is logical.
  • It keeps the human’s creative juices flowing and prevents laziness.

What Are the Limitations of AI Detection Tools?

The limitations of AI Detection Tools will always be the data it’s fed and trained on.

Because if the training data is not a good representation of the type of content the tool will be analyzing, then the results are likely to be inaccurate.

AI Model Limitation Analogy:

Imagine if you knew nothing, and I started by showing you pictures of different Chickens.

The word next to each image also says “Chicken.”

So now you have learned what a Chicken looks like without knowing any other kind of bird existed.

Now, if the following image I showed you were a duck, knowing only what a chicken is, you would think it’s similar and say it’s also a chicken.

Here are more limitations:

  • AI tools can only understand patterns and derive conclusions from them. They can have no concept of context, leading to false positives and negatives.
  • They may struggle to understand and detect more nuanced or subtle forms of content, such as sarcasm, irony, or satire.
  • Not all training data is publicly available, but sometimes it could be illegally scraped online, raising privacy, ethical or legal issues.
  • Definitely not a “let Jesus take the wheel” solution, so human oversight is still needed to review flagged content and make final decisions.
  • As AI systems are based on machine learning, they require continuous updates and maintenance to adapt to the changing nature of the content, which may require additional cost and effort.

Read my article How Does AI Detection Work if you want to find out more.

Best AI Content Detectors (FAQs)

Can Turnitin Detect AI Content?

Yes, according to them, Turnitin Originality can detect AI content.

They have been the gold standard for upholding academic integrity for decades, so you can be sure they will clamp down hard on this.

How To Check If Writing Is AI-Generated

Put the text through any AI content detection tools on this list, and you will get a probability score. This will inform you about the likelihood of the content being AI-generated.

It would be pretty tricky to tell them apart otherwise.

Are AI Text Detectors Accurate?

Yes, AI content detection tools are mostly accurate, but never 100%. They can only give you the likelihood of it being human-written or AI-generated text.

To Sum up

Alright, that’s a wrap.

No matter what industry you are in, you can stand to benefit from AI writing tools.

However, you can’t publish AI-generated content without adding a human touch.

Using AI content detection tools, ensure you don’t take Google’s or any other search engine’s policies for granted.

Checking before posting will ensure that your AI articles are spam free and safe from future core updates from Google.

I hope this helps you, and remember to share this blog post with others.

Leave a comment below if you have other exciting things to add.

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About Brendan Aw

I’m an ex-marketing executive for 6 & 7-figures high-growth startups turned writer, creator & entrepreneur. I share my learnings on digital entrepreneurship, personal finance, and remote working while helping run my family’s crystal chandelier business.

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Safeguard your content with the best overall AI detector based on 180 tests.