Region painter

How to use it

1. Choose Countries or US states.
2. Pick a colour and click a region to paint it. Click again with the same colour to clear it.
3. Click a legend label to rename the colour, for example "Visited".
4. Press PNG to download the map, or copy the link to share it.

5 practical uses

1. Make a map of the countries you have visited.
2. Colour sales territories, franchise areas or delivery regions.
3. Show where a product ships, a language is spoken or a law applies.
4. Mark the states a team covers or a licence is valid in.
5. Make a quiz or a lesson map of regions.

The maths behind it

Each region is a polygon from the TopoJSON topology, which stores shared borders once as arcs; the page decodes it to GeoJSON and colours each polygon by a property the map engine reads. The painted regions are stored in the link as their numeric codes, grouped by colour.

Notes

Countries come from Natural Earth (1:50m) with their conventional borders; US states from the Census Bureau. Small island states are small on the map, so zoom in for them. The painted areas are listed by name below the map.