https://www.vice.com/en_us/article/v7vwj3/openai-cant-detect-its-own-chatgpt-generated-text-most-of-the-time

In response to the growing concern from educators over ChatGPT’s ability to help students cheat, OpenAI released a tool on Tuesday that can detect AI-written text. However, the company said, “Our classifier is not fully reliable.”

“In our evaluations on a ‘challenge set’ of English texts, our classifier correctly identifies 26% of AI-written text (true positives) as ‘likely AI-written,’ while incorrectly labeling human-written text as AI-written 9% of the time (false positives),” the company, which developed ChatGPT, wrote in a blog post.