In France the power sockets are of type E. The standard voltage is 230 V and the standard frequency is 50 Hz.
You can use your electric appliances in France, if the standard voltage in your country is in between 220 – 240 V (as is in the UK, Europe, Australia and most of Asia and Africa). Manufacturers take these small deviations into account. If the standard voltage in your country is in the range of 100 V – 127 V (as is in the US, Canada and most South American countries), you need a voltage converter in France.
If the frequency in France (50 Hz) differs from the one in your country, it is not advised to use your appliances. But if there is no voltage difference, you could (at your own risk) try to use the appliance for a short time. Be especially careful with moving, rotating and time related appliances like clocks, shavers and electric fan heaters.
To be sure, check the label on the appliance. Some appliances never need a converter. If the label states ‘INPUT: 100-240V, 50/60 Hz’ the appliance can be used in all countries in the world. This is common for chargers of tablets/laptops, photo cameras, cell phones, toothbrushes, etc.