Electricity in France operates on 220 Volts. Electricity in the US operates on 110 volts. Therefore, American appliances do not work in France unless they have dual-voltage capability. (or unless you use a converter).
Using a voltage converter is not always totally successful. Try not to bring appliances. Hotel rooms almost always have hairdryers. Please Note: Appliances may work at partial power. In some cases a converter can damage the motor.
Adapter Plugs In France, wall plugs have round holes. An adapter is required to allow American appliances to be plugged in. Wall Plug Adapter plug with two round prongs
This French flat iron shows the French two-round-prong style plug.
Rechargeable batteries (cameras, cell phones) need an adapter plug, but not usually a converter.
Hallway Lights The French are very careful about conserving energy. In some hotels, the hallways are dark unless somebody is in them. Often you need to press a button to get the lights to come on temporarily. (Illuminated buttons are spaced throughout the hallways). Some lights are motion-activated.