Free · Join map areas

GeoJSON Polygon Union Maker

Combine two or more polygons into one polygon or multipolygon result.

Clear map preview
Private in your browser
GeoJSON download

Work with map data

Use the example or add your own GeoJSON. Results stay in this browser tab.

Polygon collection

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {
        "name": "Harbour study area"
      },
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [
              -79.47,
              43.61
            ],
            [
              -79.31,
              43.6
            ],
            [
              -79.25,
              43.7
            ],
            [
              -79.35,
              43.77
            ],
            [
              -79.5,
              43.71
            ],
            [
              -79.47,
              43.61
            ]
          ]
        ]
      }
    },
    {
      "type": "Feature",
      "properties": {
        "name": "East study area"
      },
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [
              -79.39,
              43.64
            ],
            [
              -79.2,
              43.65
            ],
            [
              -79.22,
              43.8
            ],
            [
              -79.4,
              43.76
            ],
            [
              -79.39,
              43.64
            ]
          ]
        ]
      }
    }
  ]
}

Result view

Map previewGeoJSON

Making the map resultTurf is loading in this tab.

StatusLoading

EngineTurf.js

PrivacyLocal

FormatGeoJSON

Three simple steps

How to use it

Paste a FeatureCollection with at least two polygons.
Check the combined outline in the preview.
Check the map, then copy or download the GeoJSON result.

Your map data stays on this device

Turf.js reads and changes the GeoJSON inside this browser tab. Bookify does not upload or save it. Close the tab and the working copy is gone.