The 7 Best Free ChatGPT Detectors in 2025

Everyone who’s still saying that AI is just a phase is either delusional or lying to themselves. It’s already 2025, and the reality is that language models like ChatGPT are becoming an integral part of our daily lives, disrupting industries from education to content creation. 

And as these AI systems grow more sophisticated, the need for effective detection tools has become a top priority. But not all ChatGPT detectors are created equal — many suffer from high false positive rates, inconsistent performance, and a general lack of transparency. 

In this article, I’m going to share the 7 best free AI detection tools that will have your back in 2025.

Sapling

When it comes to accurate, no-frills AI detection, Sapling is tough to beat. Developed by a team of experts from the likes of UC Berkeley, Stanford, Google, and Meta, this tool uses advanced transformer technology to identify AI-generated text with impressive precision.

What I love most about Sapling is its consistency. Detecting text from ChatGPT is one thing, but it was also more accurate than other free AI detectors even when I threw Undetectable AI’s outputs at it. Very few other free options can make that claim. You can check out our full review of Sapling AI here. 

Is it actually free? No, you’re stuck with only 2500 characters per query, so the rest of your input will be removed. You need to sign-up for a free trial or subscribe to unlock more characters per query. 

GPTZero

Another free option worth checking out is GPTZero, created by a computer science student at Princeton University. GPTZero leans on a combination of perplexity scoring and “burstiness” analysis to detect AI-written text.

GPTZero looks for patterns in language that are characteristic of human writing versus machine-generated content. The perplexity score, for example, measures how predictable the text is, which tends to be lower for AI-produced material. And the burstiness metric tracks variations in word choice and sentence structure, which humans naturally exhibit more than AI.

The one downside is that GPTZero can occasionally struggle with AI humanizers like Undetectable AI. I’ve also seen it miss some ChatGPT-generated text, especially when the model has been finetuned to mimic human writing more closely. But overall, it’s a reliable AI detector that’s improved a lot over the last year, in my opinion.

Is it actually free? To a point, yes. Their free plan has a cap of 10,000 words per month, which is something you usually won’t hit for personal use.

Copyleaks

If you’re looking for a free AI detection tool with a bit more firepower, Copyleaks is definitely worth a look. For starters, Copyleaks doesn’t just analyze text — it can also detect AI-generated images, audio, and code. 

The tool also integrates with a ton of popular platforms and workflows, from Google Docs and Microsoft Office to project management tools like Asana. This allows you to seamlessly incorporate AI detection directly  into your workflow.

In terms of performance, Copyleaks holds its own, with an accuracy rate that’s on par with Sapling. And the free plan, while limited in certain respects, still gives you a decent amount of usage before you have to start paying.

Is it actually free? Yes, but their free version doesn’t give you an AI likelihood score anymore.

Scribbr

If you’re a student, you’ve probably used Scribbr as a plagiarism detection and proofreading platform before. But did you know that they also have a free AI detection tool that deserves a spot on your radar? 

The user interface is clean and intuitive, with a straightforward upload process and clear, color-coded results. Scribbr doesn’t just tell you whether a piece of text is AI-generated — it also provides detailed feedback on specific sections that raise red flags. It’s also one of the few ChatGPT detectors that support other languages.

Is it actually free? Yes, and they also offer a premium version of their services which claims to have less false positive rate.

QuillBot

Speaking of education platforms, QuillBot also has a free AI detector that you can check out. If you’re looking for an AI detection tool that’s as user-friendly as it is effective, QuillBot should be at the top of your list. This free platform not only identifies AI-generated text, but also offers writing enhancement tools to help you improve your own content.

Is it actually free? Yes, QuillBot is completely free.

Leap AI

Leap AI is a no-code automation platform that’s branching out into different AI spaces. Recently, they’ve started offering an AI detector that’s supposed to be 97% accurate.

Here’s the thing: I’ve tried Leap against Undetectable AI before, and it actually performed way better than other detectors. When you’re that good against a tool that’s supposed to outsmart you, it’s hard not to recommend.

Is it actually free? It’s uncertain. When I try Leap, they say that I only have five AI detection checks, but it’s letting me try more than that. 

TraceGPT by PlagiarismCheck.org

Last but not least, we have TraceGPT: a free AI detection tool developed by the team behind the popular plagiarism checker, PlagiarismCheck.org. This platform lets you either input your sample text or upload a document. Many blogs hold TraceGPT in high regards, and we’re no exception. Although I’ve had better luck with Sapling, TraceGPT is no slouch.

Is it actually free? Yes! TraceGPT is free. 

Why Use AI Detectors?

AI is evolving at a breakneck speed, and we need to adapt. As LLMs like ChatGPT become increasingly sophisticated, it’s become important for content creators, educators, and businesses to have the ability to differentiate human-written content from machine-generated text.

The stakes are high — from academic integrity to brand reputation, the repercussions of passing off AI-generated work as original can be significant. Just read what some of these students are going through if you don’t believe me. That’s why AI detection tools are no longer a nice-to-have, but a must-have in 2025.

Can’t You Use Any Detection Tool?

It’s tempting to simply run any free AI detector and call it a day. After all, with so many options out there, how hard can it be to find one that works? The truth is, not all AI detection tools are created equal. In fact, relying on the wrong one can do more harm than good. 

I’ve tested my fair share of these platforms, and I can tell you from experience — many of them suffer from high false positive rates, inconsistent performance, and a general lack of transparency around their methodologies. Using the wrong tool can lead to unfair accusations, damaged reputations, and a whole lot of frustrated headaches.

That’s the reason why AI humanizers like Undetectable AI continue to attract an audience. AI detectors can’t help but fall victim to false positives, so students are starting to become proactive and use humanizers to avoid AI detection.

And if you’re wondering: yes, it works. Really well, in fact. Here’s our review of Undetectable AI as a platform and our in-depth testing against the most popular AI detectors (free or otherwise) in 2024.

The Bottom Line

AI is getting better by the second, and AI detectors are slowly but surely catching up. These seven free options I’ve highlighted in this guide are a great starting point for anyone looking to get an accurate assessment of text and avoid false positive AI detection.

But if you’re asking me which of these I prefer? I’ll say that I’m a huge fan of Sapling and will continue to be. It’s the most consistent free ChatGPT detector in my opinion, and they’re constantly improving their product while providing a roadmap into their future development.

I truly hope that there will come a day when we don’t need AI detectors anymore. But until then, you can use any one of these platforms for now. Good luck!