Why is my output empty?
If the mask covers every source polygon, no polygon area remains. Review the output count and source/mask extents before assuming processing failed.
Free · Local file processing · No account
Erase Polygon Areas Online
Subtract exclusion zones from polygons and keep the remaining areas.
Loading the local file tool…
Loading the local file tool…
How to use this tool
- 1. Choose source and overlay files, or load the working example.
- 2. Run the analysis and review the reported output count.
- 3. Download GeoJSON and inspect the result in Studio.
Limits and checks before sharing
- Polygon input only. Fully covered features disappear from the output and an empty result is valid. Mask attributes are not copied.
- WGS 84 longitude/latitude only; reproject projected data first. Keep the original and inspect known locations in the output.
- Up to 50 MB per file, 2,000 features and 20,000 vertices per layer. Polygon overlays are limited to 10,000 feature pairs. Invalid inputs fail visibly rather than being silently skipped.
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 these calculations local?
Yes. Files and calculations stay in your browser. Page resources require an initial network load. Map previews can request external map tiles. No account is needed.
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.
Add Area & Length Fields Online
Add geodesic area and line length to your dataset without overwriting existing attributes.
Check Geometry & Topology Online
Locate supported geometry issues before a polygon overlay or a data handoff.
Convert GeoJSON output to KML for Google EarthCheck GeoJSON structure before publishing