Upload your own basemap

A GeoJSON FeatureCollection or a TopoJSON topology. Each shape becomes a region, named from whichever of name, NAME, or shapeName it has. Up to 2000 shapes and 4MB.

Bringing your own map is a Creator tier feature

The Creator tier lets you upload your own basemap and build on it, for $9 a month. Every basemap that ships here, and every template on one, stays free; hosting your topology is what the subscription pays for.

The file

What the map is of

One of them is aMany of them are

Raster maps

worlda and QBAM basemaps are PNGs, and this engine is vector, so they do not work yet. Vectorizing flood-filled regions out of a raster is a different problem and it gets a proper spike before it gets a promise.