Centroid Tools Online — Extract Centroid Points from GeoJSON, Shapefile, KML and more
Centroid extraction replaces each polygon or line feature with a single representative point at its geometric centre. Use these free browser-based tools to convert area or line datasets into point layers, preserving all original attributes.
What is buffering?
The centroid of a geometry is the arithmetic mean position of all points in the shape — the "centre of mass" assuming uniform density. For convex polygons the centroid always falls inside the shape. For concave or irregular polygons the mathematical centroid may fall outside the boundary; in those cases some tools offer a "pole of inaccessibility" — the point inside the polygon furthest from any edge.
These tools compute the standard geometric centroid for each feature individually. The original attributes (name, area, population, etc.) are copied to the output point feature unchanged.
Centroids are calculated in the WGS 84 geographic coordinate system. For large polygons spanning multiple degrees of longitude or latitude, the centroid may have minor positional error; reprojecting to a local projected CRS before computing can improve accuracy.
Common use cases
Label placement
Generate a point layer for map labels — place feature names at the geometric centre of each polygon.
Distance and proximity analysis
Measure distances between polygon features by using their centroids as representative locations.
Point-in-polygon joins
Use centroids to perform spatial joins with other polygon layers when full overlay is not needed.
Choropleth to proportional symbol
Convert an area dataset to a proportional symbol map by placing symbols at polygon centroids.
Network analysis inputs
Generate origin or destination points for routing or travel-time analysis from polygon zones.
How to use
- 1
Upload your file — drop a GeoJSON, Shapefile (ZIP), KML, GeoPackage, or GML file onto the upload zone.
- 2
Process — the tool calculates the centroid of each feature and creates a point at that location.
- 3
Download the result — the point layer is returned in the same format with all original attributes preserved.
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
What happens if the centroid falls outside the polygon?
For concave or irregular shapes the geometric centroid can fall outside the boundary. If you need a point guaranteed to be inside, consider using the "pole of inaccessibility" approach, which places the point at the position furthest from any edge.
Are the original attributes kept?
Yes — all attribute columns from the original feature are copied to the output centroid point without modification.
Does it work on multi-part geometries?
Yes — for MultiPolygon and MultiLineString features, the centroid is computed over the entire multi-part geometry, returning a single point.
Can I compute centroids for lines as well as polygons?
Yes — the centroid of a line is the point at the midpoint of its total length. For polylines this is the geometric centre along the line.
Is the output always a point layer?
Yes — regardless of the input geometry type (polygon, line, multi-polygon, etc.), the output is always a point FeatureCollection with one point per input feature.