If you’re tasked with scrutinizing written content for AI usage, there are a couple of tools that can help with this, effectively. These AI detector tools, while not 100% accurate, can give you a heads up as to whether an article delivered to you is completely written using an AI service, or if it’s just some sections of the content that were written with AI.
In today’s AI-infused world, written content is now mostly done using AI writing services and apps. Well, you can’t deny the fact that, sometimes, these AI-written contents appear even better than what most human writers put out. But then, there are still professional writers who stand out in crafting 100% human-written unique content that resonates with the readers’ emotions, experiences, moods, and relativity.
Here, we will run through some of the top tools and services you can use to detect AI usage in written content.
The Best AI Writing Detectors
Here are the best AI writing detectors for marketing professionals. Again, it’s important to reiterate that these tools are not 100% foolproof. Apparently, they can be wrong with their scoring, but to a great extent, you can trust their AI detection.
1. Winston AI
Winston AI boasts an industry-leading 99.98% detection accuracy, as published by the developers. The tool is able to detect content written with multiple AI tools such as ChatGPT 4o, Claude, Google Gemini, and Llama.
The Winston AI tool is available as a Chrome extension and web application. You get a free 2,000 credits upon signing up and a 14-day free trial period, with the premium pricing starting from $12/month.
2. Undetectable AI
3. Originality.ai
For many people, including myself, Originality.ai is the go-to AI detector to use. Its scoring is about 98–99% accurate, and it searches across LLMs like GPT-3, GPT-4, Gemini, and Claude.
Originality.ai combines AI detection with advanced plagiarism checking and an API for integration into CMS workflows. Pricing starts at $14.95/month, offering up to 2,000 credits monthly with the subscription.
4. GPTZero
The name gives you some level of confidence, but it’s not about the name; this tool can actually detect AI written content with high accuracy of up to 95%. Originally developed for academic integrity, GPTZero analyzes variance and randomness in text to flag AI-like patterns.
A couple of reliable media outlets rank GPTZero as the most accurate free detector, even though it has its errors, because it does, sometimes flags human writing as AI.
5. Surfer AI
Here is another one you can trust, Surfer’s AI. This AI detector runs style-and-tone analysis using proprietary ML algorithms to deliver a probability score of AI usage in submitted content.
It integrates directly into the Surfer SEO platform, enabling editors to evaluate AI risk while optimizing for keywords. Yeah, it has a free version, but the premium version has its cost included in Surfer’s Content Editor subscriptions, starting at $49/month.
6. Copyleaks
Copyleaks and Originality.ai are my personal top picks when it comes to AI detector tools. This tool uses proprietary AI to detect plagiarism and AI-generated content by trying to understand the semantics and author style of each submitted copy.
The developers partner with LMS platforms for more accuracy and offer bulk scanning, as well as API integration. The free version is Copyleaks is quite limited, and the interface is a bit complex to understand at first.
7. Scribbr
In a 2024 testing by Scribbr, Scribbr’s premium detector achieved 84% accuracy, the highest among its alternatives at the time, while its free detector tied with QuillBot at 78% accuracy. Well, ignore those numbers, but Scribbr’s AI detector tool is one of the most accurate to use.
The company equally offers the option to request human review for critical copies. Mainly, Scribbr is for academic scholars and professional publishers alike. You can even scan articles written in a language other than English.
Feature Comparison
| Tool | Accuracy | Model Coverage | Free Tier | API |
| Winston AI | 99.98% | GPT-4, Gemini, Claude, Llama | 2,000-word trial | Yes |
| Originality.ai | 98–99% | GPT-3 to Claude 3.5 Sonnet | None | No |
| GPTZero | ~92% | GPT-3 to GPT-4 | Generous free tier | Yes |
| Surfer AI | ~90% | GPT-3.5, GPT-4 | Included in plan | Yes |
| Copyleaks | ~90% | GPT-3 to current LLMs | Limited free checks | Yes |
| Scribbr | 84% (premium) | GPT-2 to GPT-4 | 78% free accuracy | Yes |
Conclusion
Choosing the “best” AI writing detector can be challenging; hardly would two different AI detector tools give you the same detection results and scoring, so it all boils down to which one seems to convince you the most.
You can try them out by submitting an article you wrote yourself, and see if they’d detect AI writing, then submit mixed content (AI + human-written paragraphs) and see how much they can detect the AI paragraphs – that’s how to make your “perfect” pick.
