GeoJSON Tools

They fall into three groups. Inspection tells you what you have: the viewer draws a file on a map, and the validator checks it against RFC 7946 and reports each problem with the path to the member that caused it. Start here when something looks wrong and you do not yet know why.

Measurement returns numbers: area, length, centroid and bounding box. All of them are geodesic, computed on the WGS 84 ellipsoid. Treating degrees as a flat grid gives the wrong answer, and the error grows the further you get from the equator.

Transformation changes the geometry: simplify to cut vertex count, buffer to grow a shape by a distance, clip to trim data to a boundary, union to dissolve overlapping polygons into one, and merge to concatenate two collections. The optimizer runs several of these at once when the goal is a smaller file: it cuts coordinate precision, simplifies, drops unused properties and minifies, reporting what each step saved. These are the ones to check carefully, because each has edges worth knowing about, and each tool page states its own.

Converting between formats is handled separately, on the converters page.

All tools