What is a GeoJSON Polygon?
A Polygon is an array of linear rings. The first ring is the outer boundary; any further rings are holes. Each ring is closed: its last position repeats the first.
{
"type": "Feature",
"geometry": {
"type": "Polygon",
"coordinates": [
[[-73.9819, 40.7681], [-73.9737, 40.7644], [-73.9498, 40.7968], [-73.958, 40.8006], [-73.9819, 40.7681]],
[[-73.9665, 40.7838], [-73.965, 40.788], [-73.9585, 40.789], [-73.959, 40.7835], [-73.9665, 40.7838]]
]
},
"properties": { "name": "Central Park (approximate)" }
}
Rules worth knowing
- At least 4 positions per ring (3 corners + the repeated first point).
- Winding order: RFC 7946 recommends counterclockwise outer rings and clockwise holes. Shapes drawn here follow that rule; the validator tells you when imported data doesn't and can fix it.
- Holes: use the Cut tool to cut a hole (or a piece) out of a polygon you've drawn.
- Several areas in one feature are a MultiPolygon. The editor displays, edits and exports those too, and can split them into separate polygons.