AI and plagiarism detector

[enjay]

Can anyone recommend a good AI detector which is used in their school? Also, what "score" do you consider as evidence something has been AI-written? I put a few different paragraphs from ChatGPT through a checker, and it generally scored them around 55-60% AI, which I could get down to 15% using a "humaniser" tool. Some random paragraphs of my own writing were 2-3%.