Digital Geography – easy editing polygon and polyline datasets for mapping purposes

Mapshaper by mbloch is one of my favourite “swiss army knife”-tools if you need fast data reduction and topology first aid in polygon data handling. There a two versions of mapshaper. The first is a hosted webservice:, where you can easily upload .shp-, GeoJson- or TopoJson-Files via drag&drop or folder selection. Afterwards you have to chose your simplification method (Douglas-Peucker, Visvalingam or modified Visvalingam) and some other options like “repair intersections”, “auto snap” and “prevent shape removal” and you’re ready to go.