It's not bad, I like the source detector. The AI detector also does it's job somewhat ok-ish.

I did 3 ai detection, about 500 words and 3000 characters each. They used up around 600 to around 500 credits for the detection. For the first one, it was fully AI generated by ChatGPT, I got a 93.70% confirmation rate, and source detector was OpenAI, no questions there. For the second one, I changed it and added mimimal human text, I got a 72.10% AI generated. Again, no issues and works perfectly. But for the last test, I used an AI humanizer tool and immediately, the tool put it as 11.95% AI generated. This was a huge jump so I think the devs might have to work a bit on that. But again, the tool is good enough to use when you need a "quick is this AI check" before you submit something w/o the need to purchase premium plans of GPTZero.