I’ve read both- I read that the dishwasher detergent is too abrasive and can etch the paint, and I’ve also read that they are just fine to run through the wash. I won’t tell you one way or another because I just don’t know for sure, but I can say that we had corelle at home growing up that went through the dishwasher for years with no ill effects. I do a lot of looking at flea markets and antique shops and I can’t say that I recall seeing any corelle that looked like it had dishwasher wear on it like Pyrex, Fireking, and that type of stuff gets. Hopefully someone who knows for sure can chime in!