As @Rick&Jeannie posted, be sure to check your laptop transformer (or paperwork) to verify that it's 120V only. If you use a converter when it isn't needed, you could still cause damage to your laptop.
Many years ago...I had a patient on CPAP (pre dual voltage machines) that required a fuse to be changed to allow for 220V. I gave the patient the fuses and explained what to do when she got to Europe for her 2 week vacation. The first night in her hotel, she requested and got a converter from the hotel. It killed her CPAP. She ended up without a CPAP for 2 weeks.