Make a choropleth map

A choropleth map shades each area by a value, so a reader sees the pattern across regions at a glance: emissions per country, turnout per district, price per neighbourhood. The craft is in the classification. Spatly lets you shade by quantile, natural breaks, equal interval or an interpolated scale, and shows the class breaks in the legend so the map is honest about how the colour was cut.

Bring polygons as GeoJSON, or join a CSV of values to a boundary layer on a shared key such as an ISO country code. Pick a sequential or diverging ramp, set the number of classes, and tune the breaks while the preview updates. Add a popup that reads the underlying number, and cross-fade between two years to show change. The choropleth below is a real published Spatly story that steps through CO2 per capita across four decades.

Publish the map as a link or an embed, or use it as a chapter in a scroll story where the classes shift as the reader moves.