Do I need a visa for a 4 hour layover?

Hello,
I'm looking into flights from Indianapolis to Sydney & I saw one with a layover in shanghai, the layover is a little over 4 hours and I do not plan on leaving the airport. Would I need to get a transit visa,
Or would I be okay with just having my passport and boarding passes??
I'm asking because I remember having a layover in Istanbul, but they didn't require me to have any other documents since I was only there on a short layover and I wasn't leaving the airport, I just wasn't sure if China was different because of its strict laws, but I was just wondering, a layover in Shanghai would be cool.