Does Turnitin detect ChatGPT?
Yes
Yes. Turnitin runs a dedicated AI-writing model separate from its plagiarism index, and ChatGPT output is exactly what it was trained to flag.
How it works
Turnitin scores each sentence for how closely it matches the statistical fingerprint of large-language-model prose, then reports the share of the document that scored above its threshold. This is unrelated to the similarity index. A document can score 0% plagiarism and 100% AI.
The part people miss
The score is a probability, not a record of what you did. Turnitin's own guidance says it should not be the sole basis of a misconduct finding.
Flagged for something you wrote yourself?
There is a right order to handle it in, and editing the document first destroys your best evidence.