GeoJSON Dissolve Tool
Dissolve adjacent or overlapping GeoJSON polygons into one — internal borders removed, the summary shows input N → output M, and everything runs locally in your browser with nothing uploaded.
Processing and data safety
Section titled “Processing and data safety”This tool runs entirely in your browser — your files are never uploaded to a server.
Input and output
Section titled “Input and output”- Formats: GeoJSON
- Flow: GeoJSON polygons → one dissolved polygon
How to use
Section titled “How to use”- Paste your GeoJSON FeatureCollection into the input box, or click “or load a file” to pick a .geojson/.json file.
- Choose the algorithm: Standard union (turf clipping) or Shared-edge merge (adjacent polygons).
- Click “Dissolve” — the summary line reports input N → output M features; compare before/after on the map preview, then copy or download it as a .geojson file.
Key details and limits
Section titled “Key details and limits”- Runs locally via turf.js (MIT).
- Only Polygon features can be dissolved (split MultiPolygons into single polygons first).
- Two algorithms: Standard union (turf clipping — overlapping interiors are truly merged) and Shared-edge merge (TopoJSON-style arc dissolve — only shared edges between adjacent polygons; overlapping interiors are NOT boolean-unioned; output is quantized at 1e5…
Common use cases
Section titled “Common use cases”- Input: a FeatureCollection of two adjacent polygons
- Output: a FeatureCollection with 1 dissolved feature (summary: 2 → 1; internal boundary removed)