Does Turnitin detect Microsoft Copilot?
Yes
Yes. Copilot is GPT-based, and its drafting output carries the same statistical signature the detector looks for.
How it works
Same model-agnostic scoring as any other assistant. Where Copilot is used for small in-line suggestions rather than whole paragraphs, the affected share of the document is smaller and the reported percentage drops accordingly.
The part people miss
Light autocomplete inside your own sentences is a very different footprint from a Copilot-drafted section. The score does not distinguish intent.
Flagged for something you wrote yourself?
There is a right order to handle it in, and editing the document first destroys your best evidence.