I’ve used one on my glass cooktop for over a year with no scratches at all. The trick is choosing one with a smooth, flat stainless rim – no rough edges or feet that could dig in. It sits nicely on the pan rim and doesn’t touch the cooktop directly unless the pan is very shallow (rare). Mine has a wide, polished rim that glides smoothly if adjusted and stays stable during cooking. It’s reduced the oil mist on my cooktop dramatically – much easier to keep clean now. This one has been perfect for glass tops – . Safe, effective, and no issues so far.