Dissolve Geospatial Features Online — GeoJSON, Shapefile, KML and more
Dissolving merges polygon features into a single geometry — either all at once or grouped by a shared attribute value. Use these free browser-based tools to aggregate your vector data without installing any GIS software.
What is buffering?
Dissolving is a spatial aggregation operation that merges adjacent or overlapping polygon features into a single combined geometry. The result eliminates internal boundaries between merged features, leaving only the outer perimeter of the combined shape.
There are two modes: a full dissolve merges every feature in the layer into one geometry, useful for combining all polygons into a single outline. An attribute dissolve groups features by a column value — for example, merging all polygons with the same region name — producing one output feature per unique value.
When dissolving by attribute, numeric columns on the output features are typically summed or averaged from the input features. String columns that share a single unique value within a group are preserved; conflicting values are dropped or set to the first encountered value.
Common use cases
Administrative boundary aggregation
Merge census tracts or postcodes into larger regions such as districts or counties by a shared region code.
Land parcel consolidation
Combine adjacent land parcels owned by the same entity into a single boundary polygon.
Habitat mapping
Merge fragmented habitat polygons of the same type into continuous zones for ecological analysis.
Dataset simplification
Remove internal topology before publishing to a web map to reduce file size and rendering overhead.
Zoning aggregation
Combine neighbouring parcels with identical zoning codes into consolidated zone polygons.
How to use
- 1
Upload your file — drop a GeoJSON, Shapefile (ZIP), KML, GeoPackage, or GML file onto the upload zone.
- 2
Choose dissolve mode — select "Dissolve all" to merge everything, or pick an attribute column to group features by shared value.
- 3
Download the result — the dissolved layer is returned in the same format, ready for QGIS, ArcGIS, or any web map.
Supported formats
| Format | Best for |
|---|---|
| GeoJSON | Best for web maps and JavaScript tooling. Single UTF-8 text file, no auxiliary files. |
| Shapefile | Best for legacy GIS software. Upload as a ZIP containing .shp, .dbf, and .prj. |
| KML | Best for Google Earth and Google Maps sharing. |
| GeoPackage | Best for modern GIS workflows. Single SQLite file supporting multiple layers. |
| GML | Best for OGC web services and enterprise GIS interoperability. |
Frequently asked questions
Can I dissolve all features into one?
Yes — leave the attribute field blank or choose "Dissolve all" to merge every polygon in the layer into a single geometry. This is useful for creating a single outline of a dataset.
What happens to feature attributes after dissolving?
When dissolving by attribute, the grouping column is preserved. Other columns are typically dropped unless the tool summarises them. When dissolving all features, all attribute columns are dropped from the output.
Does dissolve work on lines and points?
Dissolve is primarily designed for polygon layers. Applying it to line layers merges connected line segments. Point layers cannot be meaningfully dissolved.
Will the dissolve fix overlapping polygons?
Yes — overlapping polygons within the same dissolved group are unioned, so the output geometry is topologically valid with no overlaps.
Can I dissolve a multi-geometry layer?
Yes — MultiPolygon features are treated the same as Polygon features. The output may also contain MultiPolygon geometries if non-adjacent features share the same attribute value.