Processed locally — your file never leaves your device
GeoJSON Simplifier
Reduce a GeoJSON file's vertex count with adjustable tolerance — entirely in your browser.
Drop a GeoJSON, TopoJSON, KML, KMZ, GPX, zipped Shapefile or CSV file hereor click to choose a file from your deviceNothing is uploaded — the file is detected and processed entirely on your device.
How it works
- Select or drop a .geojson (or .json) file.
- Pick a simplification tolerance — a preset, or a custom value.
- Click Simplify to reduce vertex count locally, and preview the result on the map.
- Download the simplified .geojson file.
Frequently asked questions
- Is my GeoJSON file uploaded anywhere?
- No. Simplification happens entirely on your device.
- What algorithm does this use?
- Douglas-Peucker simplification (via Turf.js's simplify, itself built on simplify-js), with an optional higher-quality, slower mode.
- What does the tolerance value mean?
- It's in the same units as your coordinates — degrees, for typical WGS84 GeoJSON. A higher tolerance removes more vertices but changes the shape more; start small and increase if the result still looks too detailed.
- Why would I want to simplify a GeoJSON file?
- Smaller file size and faster rendering — useful for large polygons or tracks with far more detail than a map actually needs to display.