With the mass adoption of AI-assisted writing, knowing whether a text was generated by a machine became a necessity for teachers, editors, and companies. AI detectors promise to answer that question, but their reliability generates debate. Here we review the best tools, how reliable they are, and what to do if your text was flagged by mistake.

You'll get to know the most used detectors, how they work, their real limits, and concrete recommendations both if you need to verify texts and if one of your own was unfairly flagged.

How an AI detector works

Detectors analyze statistical patterns of the text. They look for low "perplexity" (how predictable the next word is) and low "burstiness" (little variation in the structure of the sentences). AI-generated text tends to be more uniform and predictable than human text, and that's what these tools try to measure.

The most used detectors

How reliable they are (the uncomfortable part)

No detector is 100% reliable. Studies and specialized media like The Verge have documented significant rates of false positives, that is, human texts flagged as AI. OpenAI itself discontinued its detector due to low precision. The conclusion is clear: these tools are indicative, not verdicts.

How teachers and companies use them

Responsible use is like a warning signal, not definitive proof. Good judgment combines the detector's result with other signals: knowledge of the author's style, direct conversation, and review of the writing process, not just the final product.

What to do if your text was flagged by mistake

• Keep the history: versions, drafts, and comments prove your process.

• Show your working method: notes, sources, and previous outlines.

• Ask for a human review: remember that detectors have known false positives.

Understanding the other side of the phenomenon also helps: check out our article about how to leverage AI effectively at work to use these technologies with judgment.

Recommended Coderhouse courses

To master AI and understand its limits:

• Introduction to Artificial Intelligence Course: the base to understand how models generate and detect text.

• Content Creation with AI Course: to produce quality content with judgment.

• AI Engineering Course: for those who want to build and understand solutions with language models.

Understand AI from the inside out. Start training today.

Frequently asked questions

How reliable are AI detectors?

They are indicative, not definitive. They have known false-positive rates, so they shouldn't be used as sole proof.

Which is the best AI detector?

It depends on the use: GPTZero and Turnitin dominate in education, Copyleaks in corporate environments. None is infallible.

Can they flag a human text as AI?

Yes. False positives are a documented problem, especially in very structured texts or those written by non-native speakers of the language.

What do I do if I'm unfairly accused of using AI?

Keep drafts and version history, show your working process, and ask for a human review, remembering the limits of the detectors.