Does dissolve just merge files?
No. File merging keeps all features; dissolve performs a spatial union to remove internal polygon boundaries. Disconnected areas can remain separate polygons.
Free · Local file processing · No account
Dissolve GeoJSON & KML Polygons
Neighboring polygons share the same category and should appear as one area without their internal boundaries.
Loading the local file tool…
Loading the local file tool…
How to use this tool
- 1. Choose a polygon dataset.
- 2. Select a grouping attribute or dissolve all polygons.
- 3. Run and inspect the GeoJSON result before sharing.
Limits and checks before sharing
- Uses Turf polygon dissolve. MultiPolygons are flattened into polygon parts first; non-polygon or null geometries are rejected.
- Overlaps and invalid rings can fail. This is not automatic geometry repair, and dateline-crossing or polar data needs dedicated GIS review.
- Only the grouping attribute is retained. KML styles and assets are not GeoJSON data.
If processing fails, check the file extension and source contents. Use a smaller batch if memory runs low. The original files are never overwritten. Inspect known locations and attributes before sharing a result.
Frequently asked questions
Are my files uploaded, and do I need an account?
No. This file operation runs in your browser and needs no account or payment. The page and processing libraries need an initial network load. Opening a map preview can request external map tiles; linked resources in your original KML are not fetched or embedded by this tool.
Continue with your result
Inspect outputs directly using the result button above. Choose a compatible next operation in the result panel to continue locally without downloading again. These related links open a fresh task. Share the downloaded file through your own channels; local files are not published to a hosted URL.