Difference GeoJSON
Subtract one GeoJSON polygon mask from another and return the remaining Polygon or MultiPolygon geometry.
Input
The first input is the subject and the second is the mask; reversing them produces a different result.
Review these warnings
GeoJSON
Map preview
Understanding Difference GeoJSON
Spatial relationships and derived geometry
Subtract one GeoJSON polygon mask from another and return the remaining Polygon or MultiPolygon geometry.
Difference GeoJSON evaluates where features lie relative to one another or creates geometry from that relationship. Geometry validity, boundary rules and compatible coordinate assumptions control the result.
How to verify the operation
The first input is the subject and the second is the mask; reversing them produces a different result.
Review Difference GeoJSON with feature counts, empty outputs, boundary cases and a few known examples. Confirm units and CRS assumptions before treating the result as authoritative.