What is a collaborative map?

A collaborative map is one map that several people look at together, each on their own device, like friends leaning over the same paper map. When one person drags or zooms, everyone's map moves along, and each person's pointer shows up on the other screens with their name, so "this street here" means the same spot for everyone.

It helps whenever you plan something around a place without being in the same room: picking a meeting point, walking a friend through a route, or looking at a neighborhood together during a call.

Tool description

This tool is an OpenStreetMap map that everyone in a room shares. Open it, send the link, and whoever opens it sees the same view. Anyone can move or zoom the map, and it moves for everyone, while each person's pointer is shown to the others.

It needs no account: the room is created when the page opens, and the panel next to the map lists who is in it and has a chat.

Features

  • One view for everyone - dragging, the mouse wheel, the + and - buttons and the arrow keys move every map in the room
  • Live cursors - each pointer appears in its owner's color with their name, and a tap on a phone shows where it touched
  • Cursors off your screen - on a smaller screen, a pointer outside the visible part of the map waits at its edge, pointing toward where it is

How it works

The room on the sync server keeps the view every map shows, its center and zoom. When you move the map, your browser sends the new view, at most ten times a second while you drag, and the other maps glide after it. If two people move the map at the same moment, the last move wins and everyone ends up on the same view.

Pointers are sent as map coordinates, not screen positions, so a pointer lands on the same street on every screen, whatever the window size. The server sends each person all the moves since its last update once every tenth of a second, and nothing while nobody moves, so a full room stays smooth.

Limitations

  • A room holds up to 20 people.
  • The map always shows the room's view. To look around on your own, leave the room; the map stays where it was.
  • Nothing is saved. Once everyone has left, the room is gone.

Tips

  • Reloading the page keeps you in the same room, at its current view.
  • Your pointer shows only while it is over the map. Move it off the map to hide it.