Do Coinstar machines in the United States take Canadian coins, too?
I know that is a stupid question, but I’ve never tried to put Canadian coins through a Coinstar machine. I live in Michigan and I have a jar of coins I want to convert, but a lot of the coins are Canadian.

no, i put one in on accident and it spits it out.
Just try to pour all your coins in the machine including the Canadian ones. If it doesn’t get accepted, it should go through the machine and come out at the bottom.
Try it out. One of the first Coinstar-type machines I tried was in the U.S. The coins that were rejected were returned to me. I don’t think that the coins would automatically be converted to U.S. by exchange rates though. It would probably be beyond the scope of those machines.