which card to use on the Paris metro

The photo size is 25 mm by 30 mm (1" by 1 1/4"), slightly smaller than passport size.

Another option is to buy a Navigo Easy Card with no picture for 2 EUR, then load a certain number of Metro Tickets onto it at 2.50 EUR per trip. If you take no more than 10 trips, it will be less than the cost of the weekly Navigo Decouverte.

I find the various card types confusing as well. I'm only in Paris for a few days, so I'm planning to go to a smaller, less busy metro station to purchase a Navigo Easy card and load it with maybe 5 metro and 5 bus trips. If I need more, I'll add more. Honestly, I'm still not sure this is the best course of action, even after having read many things here and on other sites as well as watching a few YouTube videos. There are so many "if this then that, but if this then that" caveats that would probably start to make lots of sense if you were in Paris for months, but are confusing at this moment.

There are 2 physical cards you can use to load passes or tickets. Which one you want depends on several things.

The Navigo Découverte is €5 and requires a photo,. It is valid Monday to Sunday and can be loaded with daily, weekly and monthly passes.

The Navigo Easy is €2 and no photo needed. It can be loaded with multiple single bus and metro tickets.

Where do you want to start using public transportation in Paris? At a train station, the airport or elsewhere? What days will you be starting and ending your use of Paris public transportation?

The Navigo Découverte is a nontransferable card requiring the user's name and photo. It may be loaded with either the weekly pass (M - Sun) at 31.60€, or a monthly pass (calendar month) 88.80€.

The Navigo Easy card is transferable, accepts tramway/bus tickets (2€), métro/Transilien/RER tickets (2.50€), or airport tickets (13€) or the day pass (12€)

And the Navigo Easy is reloadable from your cell phone with the Bonjour RAPT app. You can load metro or bus tickets - these are 2.5e or 2e - in preset increments of 1, 3, or 10 tickets. You can also check your last three validations and see how many rides of which kind you have left. You can check multiple cards from one phone and you can load trips using your phone pay if you have that set up. It's super easy and the longest part of the process is typing in your email for a receipt.

I have to say I think the system is probably the best big city mass transit system I've used. Being able to check how many trips you have and then load more in your hotel room or at dinner before you leave and not having to do it in the metro station is great. We mostly used the metro but if you decide to take a bus during a day out add a bus ticket while you wait at the stop and then just tap as you get on.

You didn't ask but also very impressed with the City Mapper app in Paris - definitely better than Google maps which is "okay" for simple trips but is sometimes wacky in its suggestions for longer/more complicated trips. City Mapper also includes details like which car or station entrance/exit is best.

Enjoy Paris - it's an great city,
=Tod

The nagging difference is that the ticket to ride to the airport is not the Navigo Easy card. If you intend on taking the RER B to CDG, the Navigo Easy won't do it.

I go to a machine to reload my Navigo Easy cards, which I bought from the machine.

Can't help with the Decoverte Pass

My brain can only handle so much thinking and planning at a time, so for our recent Paris stay from Tuesday through Monday I got the Navigo Decouverte pass.

I made photos at home on my printer, using regular paper, that fit the required dimensions, then stuck them in an envelope to use when we got there. Our only hiccup was finding a station with an attendant to buy from. So, if you opt for the Decouverte, maybe ask on the forum about the closest metro station with an attendant to your hotel. I asked the attendant politely with my limited French for the pass and he put it together for me. From that point on it was just tap and go on buses, metro and the RER we needed to Versailles.

Using more technology works for lots of people, but I wanted to keep my trips as simple as possible. I would have used my Navigo Easy pass if we had been there fewer days. We’re in the senior demographic, so it’s not easy to guess how many trips we’ll need upfront.

To give a little clarification to Fred’s post. It is possible to load an airport RER ticket on a Navigo Easy Card. It just has to be a different card than those with metro, bus or tram. Easily purchased at ticket machines at the airport. 2€.

Further clarification - airport tickets (13€) may not be loaded onto any Navigo Easy card containing métro/Transilien/RER tickets, and visa versa. Tramway/bus tickets on an Easy card do not block the addition of airport tickets, and visa versa