This is from far the best solution. Contact your phone provided at home and check their International plans including Europe/France. 

• It usually costs about $10-15 a day and this is worth it for using the GPS on your smartphone (Waze, Google Maps, etc)
• On average, our travelers use about 50MB/day (for GPS & keep in touch with home). For a 2 week trip, plan on using about 1GB for this type of use.

You may buy a prepaid French sim card either at the airport or even from home on Amazon. 

You may check the prepaid sim cards from "Bouygues" or "Orange" phone operators. 

Be careful: 

• Your phone needs to be unlocked to European sim cards.
• Make sure that the duration of the prepaid card covers your trip (some are 2 weeks and others 1 month - after first use)

Free Wifi is accessible in all accommodations. 

Also, more and more restaurants, museums, public places have free wifi. 

The Wifi quality is better in bigger towns and slower in the countryside. However, this tends to change as all the French territory is getting equipped with fibre-optic network.

GPS & Keep in Touch use

On average, our travelers use about 50MB/day for GPS & keep in touch with home.

For a 2 week trip, plan on using about 1GB for GPS & keeping in touch.

Watch Movie or Send lots of Pictures

If you like to watch a movie or serie at night, we warmly recommend connecting to your accommodation wifi to do so.

If you send lots of pictures home or upload them on your drive, we also warmly recommend doing so while connected to a wifi (not using your phone data). 

• 97% of the French territory is covered with 4G (with stronger or lesser strong signal...)
• 70% of the French territory is covered with 5G (mostly in bigger cities)