Little A Map - A tool that pieces together your in-game maps to show online - eviltoast
GitHub - AndrewKvalheim/little-a-map: Players can have little a map—if they've surveyed the area in-game. This tool renders a composite of player-created map items with the goal of minimizing external effects on survival gameplay.
github.com
Players can have little a map—if they've surveyed the area in-game. This tool renders a composite of player-created map items with the goal of minimizing external effects on survival gameplay. ...

I was looking through the mapping software listed in the Minecraft wiki when I came across Little A Map.

Most mapping software (e.g. Dynmap and Squaremap) obsoletes maps that you can make from the cartography table by rendering their own.

Little A Map takes a different approach to mapping: instead, it pieces together every map you make in-game. Whatever zoom level you made your map determines the quality of the map displayed by the program. It also supports showing banners (along with names, too), so you can mark waypoints without ever leaving the game.

If you want a map to share with friends online, but also want to preserve the mystery of exploration, I think this would be an interesting program to check out.