Map of the INSIDE of Metro stations

Start here, many apps available, just google.

https://www.ratp.fr/en/plan-metro

There's an app called Paris Metro that has a paid, premium version that will show you door locations and which carriage location is best for where you need to exit. I don't think it has routing from one line to another, though. For Paris metro plan on lots of walking and stairs. There is good signage so if you follow signs for your next train line you should not get lost. Just be sure to check the stops map so you get the train going in the right direction.

Any particular change point you are interested in?

The City Mapper app tells you which entrance is best for the start of the trip, where on the train you should be (not a specific car but front, middle, or rear) and which exit to use when you get to your destination. Www.Citymapper.com. It does not tell you the distance but it tells you how long it thinks it will take an average walker to make a connection or get to the metro station or get from the metro station to the destination action.

Thanks for the info! I'll check these options out. Sam, we are transfering from RER B to RER C at St Michel.

Believe it or not, I actually scoped out this station about 8 years ago. I was staying near Austerlitz station and was looking for a way onto the RER B to the airport with a heavy suitcase. I crossed this off the list.

The RER B is several levels below the RER C. The RER B has just crossed underneath the Seine in a deep tunnel. The RER C is on an old railroad bed that ran long the Seine, so it is obviously above the level of the river. Without heavy luggage it would not be a problem. Just follow the signs.

RER B in which direction to RER C in which direction? I don't remember anything about this connection except that I vaguely recall that the trains are on different levels but I hope that someone who has done the transfer recently can offer some pointers.

JHK coming from CDG, going to Versailles.

Citymapper will give you all the required information for an easy connection.

Indeed, as Tocard and JHK have mentioned, CityMapper does all this for you. It's by far the best solution.

The B-C connection at St Michel is not particularly long or difficult; there are escalators most of the way and they leave from roughly the middle of the RER B platform. More difficult is stepping onto the C trains at St Michel, because the platform is very low: you have 2 big steps between the platform and the level of the train.

Thanks so much! I have a better idea now!

This blog includes photos of some of the main station, helpful in orienting your visit.

https://parisbytrain.com/

I don’t have any helpful tips because on my recent trip to Paris I had no idea how huge some of those metro stations are. I really got lost trying to find my train in one of them and it took me a half hour to get to the right platform after asking two workers to help me! Good luck!