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6 Best AI Writing and Plagiarism Checkers for Teachers

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Updated by Justin Gluska on April 9, 2024 in ,
With the recent rise in AI writing software, teachers have seen tons of artificially-produced writing over the last few months. With this comes the rise of AI detection tools that analyze and predict text patterns to help determine if something was likely written with the assistance of AI. Here's a few of our best tools we've came across over the last few months 
Best Overall
Winston AI
Winston is a great tool for educators and students looking to verify academic instances of AI. It easy, supports OCP, and offers a high detection accuracy rate.
Best Free & Accurate
Copyleaks is great for checking single articles of writing. It's accurate and has a generous free plan.
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Best for Tons of Writing
Originality AI
Originality is great for bulk-verifying a lot articles, quickly. It has an easy-to-use interface which provides results in a few seconds.
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Best to Visualize AI Writing
Passed AI
Passed AI has quickly cemented itself as the AI detection tool to visualize student writing. This makes it easy to see if somebody copy-pasted into Google docs.
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Academic integrity is a critical factor in education, and the introduction of AI writing tools haven't helped. AI tools like ChatGPT pose major threats to the modern education system.

It's becoming easier and easier for students to use AI writing tools to pass off fully AI-generated work as their own. We've entered a grey zone where educators are facing a constant battle to detect and prevent AI plagiarism.

With this recent AI boom, tools have popped up that help predict the presence of AI writing by finding patterns in submitted text. With the use of advanced algorithms and natural language processing models, AI plagiarism detection tools are meant to quickly identify instances of AI plagiarism regardless of assignment size.

I do want to emphasize the word predict because that is how these tools work. You can't "prove" AI like you can with plagiarism.

How Does AI Writing Detection Work?

Although not mathematically provable, AI writing detection tools try to re-predict the same text you're trying to test. Because AI works on patterns, it generally produces fairly consistent text structures.

Currently, you can't have AI accurately write things like recent product reviews or creative analytical opinions, but AI is great for analyzing static content like historical events, books, and textbook content.

Since humans are so versatile and complex, human writing doesn't include as many predictable patterns & sentence structures. The best writers often have an unpredictable vocabulary that engages and questions their audiences in ways Artificial Intelligence cannot currently do.

AI writing follows formulaic patterns of what it was trained on, since that's what it knows best. The more accurate a detection tool can recreate the same sentences you are trying to detect, the higher chance what you're looking at has been written by or at least assisted by AI.

If you want more of an in-depth explanation, check out our more technical explanation.

Just recently, students have been accused of using AI-generated writing because of TurnItIn's new AI detection software. I'm sure some of them were innocent and just happened to get flagged by these tools.

Again, these tools should be taken with a grain of salt.

Claiming a single piece of paper was written with AI because of the result of a detector is still not proof that a student used AI. I've written tons of articles that have me flagged as using AI when I didn't use anything at all. These tools can help you predict, not determine.

Just remember if you're using any of these tools to detect student AI writing, take the results with a grain of salt. These results are just predictions and multiple rounds of analyzing text should be made before validating if something was written with AI.

While I wouldn't fully rely on AI detection tools if you are a teacher, they can be decent indicators when tested on multiple instances of a students writing.

The last thing you want to do is accuse a student of using AI just because you tested a single article they wrote. I hate to break it to you, but this can of worms can not be solved this easily. It's probably never going to be solved.

Want to avoid this headache? Just have students write and submit things on paper in class. Sounds old school but it's the only headache free method that is actually perfect.

Regardless, in this article I'll still talk about the best AI plagiarism detection tools for teachers and educators that are trying to battle the newest wave of tech. These tools are all aimed at helping educators ensure that the work their students are submitting is original and authentic.

We've tested each one of these detectors thoroughly on an abundance of both short and long-form content. As new detection tools and technologies are released, we'll test them and replace them on this list.

The Best AI Writing Detection Tools for Teachers in 2023

Tools like ChatGPT are nothing short of incredible & have resulted in tons of new creations, essays, and business ideas around the world. But with that comes cheating.

Each of these detection tools work slightly different & carry certain purposes over others. Convenience is also a big issue, especially if you're testing 30 pages of essays each day. With all of this in mind, here are the current best AI text detection tools currently on the market:

1) Copyleaks (free & easy)

I'd say Copyleaks is one of the best out of the box. It's simple, has a free plan, and takes a few seconds to get you a verdict.

A recent research paper from Cornell University found that their AI detector is the best at spotting text made by AI tools like ChatGPT (especially the newest update which includes GPT-4) and Claude.

They claim to be 99.1% accurate and can tell if the text was written by an AI in more than 15 languages. It shows which parts are likely made by an AI by highlighting them (but this isn't as accurate as the holistic score).

It can claims to find content that was reworded from AI-made text. You can use a basic version for free, but if you pay $10.99 a month, you'll also get a plagiarism-checking feature.

2) Winston AI (built for teachers)

If you're looking to bulk test academic/education content, Winston is your go-to. Winston AI self proclaims to be the best academic AI detection software.

It's similar to Originality, but focused specifically on educators looking to check for students who used AI. You can start for free but need to upgrade if you have a larger quantity of papers to check.

Winston AI dashboard showing student writing as being human-written, plagiarized, and at an 8th grade reading level.

When you submit a document, you'll get a human score (based on the likelihood a student wrote it using AI), a plagiarism score (with links to the writing it was stolen from), and a readability score (with the reading level of the content).

These all work together to give you a pretty solid understanding of where this writing came from. If you see university level writing for a middle school english class, something is probably up.

Winston is super easy to use, supports OCR (you can upload written documents and have it scan a specific essay to check for AI), and is extremely fast.

Winston also lets you generate a report in 1-click, very great if you want to show your students insight into why they were flagged as using AI. Pretty awesome, right?

Winston AI detection and plagiarism report for teachers

If you do anything in the educational sector, you need to check out Winston!

3) Originality

I've been using Originality's AI detection tool since the January it came out to check various types of content (academic papers, business industry reports, and online blog posts).

It's fast, easy, and accurate. Originality claims to be made for serious content publishers over those in academia, but its UI, flexibility, and visualization are vasty ahead of other tools, especially when checking a ton of submissions at once.

Originality costs 1 cent per hundred words, making it one of the most affordable options to check many papers in a short time. To put this into perspective, to check 30 essays each around 1500 words, will run you about $4.50.

Compared to other tools, Originality also includes a percentage in its prediction score. You'll see something was 2% likely to be AI and only 98% likely to be human written (these will add up to 100). Here's what it looks like in action:

Student written essay entered in for AI detection

A great feature about Originality is line-by-line highlighting. You'll see sections marked in orange which represents it might be written with AI. Green sections show human-writing. The more text you enter, the larger sample size Originality has to work with (increasing the reliability of your result).

As you can see below, a decent amount of the paragraph was highlighted in orange, but as a whole the article is in the clear. (This is true, I tested it with a college academic essay!)

Originality AI detection results for student-written essay. Not written with AI

4) Undetectable AI Plagiarism Detector

Undetectable AI has an AI Plagiarism Detector that can help determine if something was written with some of the popular AI text generators (aka ChatGPT and Claude). It's fairly good at detecting when someone used any of these tools to write something and will even give you a breakdown of why it flagged something:

ChatGPT writing submitted to undetectable AI's AI Plagiarism Detector

5) Passed AI

Passed.AI is a newer AI detection tool that is specifically for teachers. The model is trained on GPT-J, GPT-NEO or GPT-3 to detect AI writing based on patterns. They further claim to be trained on GPT-4 directly from Originality (but they still tailor the rest of their features specifically for educators).

They also have a Chrome Extension for quick-checking documents, which you can even do inside of Google docs. A unique feature about passed is how they let you "replay" a Google doc to see edit history. This is great for auditing an entire document based on how it was written

The company claims that AI Detection alone is NOT enforceable. But when combining AI detection with a document history audit will provide an unparalleled confidence in AI detection. All you need is edit access to the Google document the student submitted and Passed.AI can provide you a detailed audit.

  • "Replay" at 10x speed
  • See the number of contributors and the size of their contributions to the text
  • See if the words/minute were natural or not
  • No software for students to install

The actual AI detection page is similar to any other software. To use, paste suspected text into the scanning box and start scanning. You'll get a percentage score indicating the likelihood a sample was written with AI. A score of 100% Not AI and 0% AI should be thought of as "We are 100% confident that this content was created by a human."

Passed AI detection result showing that sample text is 100% written with AI

6) Content at Scale

The next tool we'll talk about is called Content at Scale. If you're looking for an AI detection tool that tends to not over-flag people, this is probably it.

I've tested old academic essays, ChatGPT responses, and random articles I found online and have found the tool holds up very well, but doesn't like to claim something as AI if it's not true.

This detection software is also free, it's just a bit harder to test dozens of articles quickly with it. I would give this tool the highest AI detection score as it's based on a ton of advanced language learning models.

The company behind this actually creates fully written, complex website blogs; so they built a detection tool to see if their writing is able to be detected by AI (it's generally not!). Here's a few examples of an academic research paper, poorly written paper, and ChatGPT answer:

100% human written text detected with content at scale
43% human written text detected with content at scale
0% human written text detected with content at scale

7) GPTZero (individual academic content)

The next resource that could be used in detecting AI writing is GPTZero. This tool was actually created by a student at Princeton in early January. It works by assigning text both a perplexity and burstiness score. Perplexity measures how random the text is while burstiness measures its variation. The higher both of these values are, the more likely the document was human-produced. We have a complete review on GPTZero if you want to learn how it works.

The tool also includes feature that will highlight text that might be written with AI (if it's only a few lines in an essay, compared to the entire document). Again, these tools should be used with your own judgement, but it's a good initial starting point if you detect something was written by some AI-writing software.

You can use GPTZero by uploading a full document (as a pdf, docx, or txt) or pasting text directly into the tool. Once uploaded, you'll see the predicted result in large bolded text.

Text may include parts written with AI from GPTZero

You can see what text had been predicted as likely AI if you scroll down. This text will be highlighted in yellow and can appear at any point or sentence throughout a submission.

Possible AI generated text analyzed with GPTZero

You'll also be provided with the perplexity and burstiness scores of the submission, but these scores don't really tell you anything beyond the scope of their definitions. It's best to use GPTZero based on its final prediction & color flagging.

Article perplexity and burstiness scores from GPTZero

Final Thoughts

All of the tools on this list serve their specific purpose. Before going all in on one specific AI detection tool, you should carefully consider the features and use cases for each tool, as well as features that would best align with your classroom and school standards.

Remember to take the concept of AI detection with a grain of salt as there are many ways to help detect content that include your very own judgement. Keeping all these things in mind, you can always test out various detection tools to see what fits right for your assignments and workload.

Have I missed any of your favorites on this list? Which of these detection tools have you had the best luck with? Let me know in the comments!

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Written by Justin Gluska
Justin is the founder of Gold Penguin, a business technology blog that helps people start, grow, and scale their business using AI. The world is changing and he believes it's best to make use of the new technology that is starting to change the world. If it can help you make more money or save you time, he'll write about it!


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