For example, the sharing map strings for my actual map is 980 char long.
So less than 1KB for the 1st layer.
You take the savegame as strating point, but saves contains much more that you can see.

I'm pretty shure that is possible to be under the megabyte for a map. Maybe even less. A developper ...

As only the position of the tiles has to be saved (not the tiles themselves) it mustn't take so much place (less than a 500 Mpx picture at least)
To represent the complete factory I see 3 layers:
- The terrain layer, the biggest one in size, but maybe it can be generated identically from the map ...

TL;DR
Make screenshot of big factory is complicated, be able to upload screenshot on an online service that everyone can browse our map like in google map would be great.

What ?
An online service that provide the ability to see factories likes in google maps. From the game we can send the ...